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1. Because I Feel Like It by FiresideCommulist

   Fandoms: Phineas and Ferb  

   • Explicit
   • No Archive Warnings Apply
   • F/F, F/M, Other
   • Complete Work

   21 Dec 2025

   Tags

   • No Archive Warnings Apply
   • Phineas Flynn/Isabella Garcia-Shapiro
   • Phineas Flynn
   • Isabella Garcia-Shapiro
   • Genderfluid
   • Genderfluid Character
   • Trans Character
   • Trans Female Character
   • Sex
   • Sex Toys
   • Vaginal Sex
   • Angst
   • Fluff and Angst
   • Angst and Fluff and Smut
   • Angst with a Happy Ending
   • Angst and Feels
   • Romance
   • Established Relationship

   Summary

   Phineas is excited to reveal that she is now a girl, at least for the moment. However, the reactions she receives are more complicated than she expected, including from Isabella, her girlfriend. Rated Explicit for sexual content.

   Language:

   English

   Words:

   6,045

   Chapters:

   4/4

   Comments:

   6

   Kudos:

   9

   Bookmarks:

   4

   Hits:

   349