41 - 60 of 2,027 Bookmarked Items in Ecto-Penis (Undertale)

Navigation

List of Bookmarks

  1. 30

    Tags
    Summary

    Ink has had no reason to learn about sex until today. From then on, it's become a bit of a thing between him and Error. But only Ink and Error would make sex into a competition.

    Language:
    English
    Words:
    19,536
    Chapters:
    14/?
    Comments:
    78
    Kudos:
    323
    Bookmarks:
    30
    Hits:
    6,318
  2. 20

    Tags
    Summary

    A quick fluffy oneshot with Underswap Sans and you, the reader, in first person pov, about a massage given to a very touch-averse person. (Hint: that's you!)

    First work ever, comments and feedback are very much appreciated!

    (thanks VERY much to Ravenxxx97, who helped me edit/ proofread this- I love you <3)

    Language:
    English
    Words:
    2,876
    Chapters:
    1/1
    Comments:
    14
    Kudos:
    156
    Bookmarks:
    20
    Hits:
    2,052
  3. *

    Tags
    Summary

    Papyrus and his Detective partner (you) have to solve a missing persons case. It turns into a huge undercover operation where you still have to rescue the missing person: Sans!
    Along the way there's shenanigans, swearing, sex, misunderstandings, bad puns, and you fall in love with your spiky partner's brother.

    Language:
    English
    Words:
    73,537
    Chapters:
    21/?
    Comments:
    220
    Kudos:
    546
    Bookmarks:
    109
    Hits:
    9,106
  4. 9

    Tags
    Summary

    Prince Cross is so endearing to Fae Dream that as the Fae prepare to slaughter the mortal Kingdom for King XGaster's insolence, he's stolen away on a whim. This has consequences.

    Series
    Language:
    English
    Words:
    9,072
    Chapters:
    1/1
    Comments:
    10
    Kudos:
    66
    Bookmarks:
    9
    Hits:
    981
  5. 21

    Tags
    Summary

    Cross returns from another successful mission ready for some alone time when his Boss finds him and decides it's high time his loyal soldier is given his reward.

    Language:
    English
    Words:
    3,798
    Chapters:
    1/1
    Comments:
    4
    Kudos:
    229
    Bookmarks:
    21
    Hits:
    2,857
  6. 55

    Tags
    Summary

    Several weeks have passed since you fell into these labyrinthine subterranean caverns. It's time for you to move forward.

     

    [Explicit Sans x Reader, the reader insert's sex is undefined and can be interpreted as either male or female.]

    Language:
    English
    Words:
    2,561
    Chapters:
    1/1
    Comments:
    25
    Kudos:
    1,379
    Bookmarks:
    55
    Hits:
    27,491
  7. 29

    Tags
    Summary

    Papyrus wants to take your relationship to the next level, and he has a crafty plan to make that happen.

    Written for the 'Let Papyrus Fuck' 2022 event.

    Language:
    English
    Words:
    2,223
    Chapters:
    1/1
    Comments:
    16
    Kudos:
    315
    Bookmarks:
    29
    Hits:
    2,978
  8. 54

    Tags
    Summary

    You spend some time with Killer and Nightmare.
    Even though both of them are very keen to help you have a good time, can they actually work together, or will those little sparks of jealousy between them get in the way?

    Should you be a brat and do a little instigating? Absolutely. Just a little. As a treat.

    Language:
    English
    Words:
    5,773
    Chapters:
    1/1
    Comments:
    15
    Kudos:
    499
    Bookmarks:
    54
    Hits:
    7,410
  9. 20

    Tags
    Summary

    Ink was infuriating. However —to his bad luck— It wasn't a wonder how Nightmare let him do whatever he wanted. Was it really weakness if the thing disarming him was love? When would Nightmare draw the line, if he ever tried?

    or

    Was it really a bribe if that wasn't the initial intention / he genuinely just wanted to have a taste of the good old arbor vitae?

    Series
    Language:
    English
    Words:
    10,469
    Chapters:
    1/1
    Comments:
    26
    Kudos:
    127
    Bookmarks:
    20
    Hits:
    1,955
  10. 20

    Tags
    Summary

    While hiding their relationship had its charms (adrenaline was one hell of a thing), it wasn't very often they could enjoy some time alone. They'll definitely make the most of it.

    or

    Ink and Nightmare kiss 40 times, keep talking for some reason and end up doing it out of wedlock (good)

    Series
    Language:
    English
    Words:
    10,669
    Chapters:
    1/1
    Comments:
    18
    Kudos:
    195
    Bookmarks:
    20
    Hits:
    3,060
  11. 12

    Tags
    Summary

    Nightmare has always been distant from his gang for multiple reasons. But deep down, he does love them. How does he show his affection towards them while having plausible deniability? Sex.

    Language:
    English
    Words:
    8,215
    Chapters:
    4/5
    Comments:
    5
    Kudos:
    89
    Bookmarks:
    12
    Hits:
    1,651
  12. 14

    Tags
    Series
    Language:
    English
    Words:
    1,451
    Chapters:
    1/1
    Comments:
    8
    Kudos:
    183
    Bookmarks:
    14
    Hits:
    5,196
  13. 9

    Tags
    Summary

    This was supposed to be a normal movie night...
    How the fuck did it turn out this way?

    Yk ur classical corny movie 🌽 shit trope

    Why did I let Kwaz talk me into this again...?

    I did not have any ideas for the title do not judge ms

    Language:
    English
    Words:
    1,764
    Chapters:
    1/1
    Comments:
    3
    Kudos:
    114
    Bookmarks:
    9
    Hits:
    3,193
  14. 96

    Tags
    Summary

    You’ve just moved in with your girlfriend into her mansion filled with skeletons.

    Thinking you were just going to stay out of their way, it turns out most of them have a crush on your girlfriend!

    Well guess it’s time for you to show them who’s boss.

    Language:
    English
    Words:
    54,808
    Chapters:
    21/?
    Comments:
    141
    Kudos:
    471
    Bookmarks:
    96
    Hits:
    8,492
  15. 24

    Tags
    Summary

    Collection of various soft and spicy moments between you and Horrorfell Sans

    Language:
    English
    Words:
    1,228
    Chapters:
    5/?
    Comments:
    6
    Kudos:
    218
    Bookmarks:
    24
    Hits:
    3,302
  16. 42

    Tags
    Summary

    My first time writing smut and it’s for a Kinktober LMFAO
    Sans (Aus) x Reader smuts only :)
    MOSTLY dom reader <33
    ill update the tags as i go!!

    Language:
    English
    Words:
    15,423
    Chapters:
    8/31
    Comments:
    28
    Kudos:
    552
    Bookmarks:
    42
    Hits:
    15,187
  17. 5

    Tags
    Summary

    You honestly can't remember when you had officially moved into the lodge to be with your datemate. It started as leaving things in his room under the (flimsy) excuse of having stuff for the next time you have an impromptu sleepover—but it was a not-so-subtle takeover.

    The others didn't mind it either and were gracious enough to provide you with your own room for when everyone's shenanigans prove to be too much for you, but little did they know that they practically invited the devil herself into their home, because you're the queen of starting some bullshit or doing things for the bit.

    Language:
    English
    Words:
    4,278
    Chapters:
    2/?
    Comments:
    3
    Kudos:
    15
    Bookmarks:
    5
    Hits:
    403
  18. *

    Tags
    Summary

    You and Sans have spent the last five years toiling in the lab on your magnum opus: a looking glass into alternate timelines. But when you test it one late night in the lab, the impossible happens and you are taken into a world much more violent and crueler than your own. Needing to survive until you're rescued, you will have to use all your wits, charm, and determination to convince three paranoid skeletons you aren't insane or a spy. Good luck, doll.

    Language:
    English
    Words:
    105,124
    Chapters:
    20/?
    Comments:
    363
    Kudos:
    789
    Bookmarks:
    192
    Hits:
    21,134
    • 12 Dec 2025

      Public Bookmark

    • 27 Oct 2025

      Public Bookmark

    • 23 Oct 2025

      Public Bookmark

    • 16 Oct 2025

      Rec

      Bookmark Notes:

      Despite the spelling errors, it's a really brilliant fic. I really like everyone's characterizations and how real everyone feels.

      It's good to see that thing's have cleared up in chapter 20- and that the house arrest is finally over... Really wondering what would happen next- especially now that Sans knows it wasn't all a lie.

      Hoping for updates. Ch. 20

    • 12 Oct 2025

      Public Bookmark

  19. *

    Tags
    Summary

    It was a nightmare for you before you finally left the mansion. Heather had them all wrapped around her finger and made your life hell. At least you finally got away.

    Then three years later you see on the news- the mansion was used for monster trafficking. The darker parts of society in other countries were always looking to get their hands on a monster to study.

    With the autonomy Sans was afforded by monster society, royal guards and police never suspected the mansion was where monsters were being kept imprisoned after being kidnapped. A bloody and violent escape attempt finally exposed the secret. Now all the monsters imprisoned are free, including the skeletons who were chained for two years.
    You want nothing to do with it, but there was one skeleton you did care for- Mutt. His brother was dead and who knew what traumas he faced in the mansion. He helped you get on your feet when you left. He was there when you needed him and it was time to return the favor, regardless of who else you might meet...

    Language:
    English
    Words:
    45,552
    Chapters:
    16/?
    Comments:
    531
    Kudos:
    1,469
    Bookmarks:
    334
    Hits:
    31,061
  20. 7

    Tags
    Summary

    It was Tav's birthday, and she was back in the Elfsong. But this time she was naked, tied to a bed with her legs spread, blindfolded, and she was almost trembling with excitement and arousal.

    Birthday gangbang, female Tav with no description. She's had all the companions separately... now she wants them all at once. Entirely, unapologetically smut.

    Series
    Language:
    English
    Words:
    2,898
    Chapters:
    1/1
    Kudos:
    104
    Bookmarks:
    7
    Hits:
    3,777

Filters

Filter results:
Submit

Include

?
Include Ratings
Include Warnings
Include Categories
Include Fandoms
Include Characters
Include Relationships
Include Additional Tags
Include Bookmarker's Tags

Exclude

?
Exclude Ratings
Exclude Warnings
Exclude Categories
Exclude Fandoms
Exclude Characters
Exclude Relationships
Exclude Additional Tags
Exclude Bookmarker's Tags

More Options

Bookmark types
Submit

Clear Filters

Navigation