Anime/Vocaloid x reader (lemons/fluff)

Quick question

I want to write a character x self conscious reader fluff (but I can't control it if my hand slips ( ͡° ͜ʖ ͡°)) I just don't know what to make the reader self conscious of

I was thinking maybe weight or chest size but I'm still unsure, I wouldn't mind some help with that sweethearts!