I texted my roommate and asked if he could buy me Skittles on the way back from work, and he said yes. When he got home, he handed me Wild Berry flavored Skittles and Venmo requested $2.50 for them. The thing is, I have a severe repulsion/phobia of berries and berry flavoring, something I am extremely vocal about. I have known my roommate for over 15 years and know for a fact that he is aware of my aversion to berries. Even though I believe he made an honest mistake, I really don't think it's fair for me to have to pay him given that I will not eat those Skittles and given that he knows I would never eat those Skittles. To me it's akin to asking for jelly beans and him buying me vomit flavored Jelly Belly's and then Venmo requesting me for it. For some reason he refuses to accept that I will not eat the Skittles and thinks it's "embarrassing" that I don't like berries. I really just don't think it's fair that I should pay for the Skittles even though I know he was trying to do a nice thing for me. AITA for refusing to pay?