anal ...... lol

okay i have always always always been the kind of girl who was 110% against it. But i was with my boyfriend and we were making out. So we haven't had sex yet (i don't feel i'm ready and he respects it completely) thus he asked if he could put it in the back, he didn't beg or force me but i let him to make him happy. (it lasted less than a minute and we have done another maybe 4 times; all lasting 30 seconds or less before i make him stop) but i honestly feel like a total FREAK and a gross weirdo. Is this common??? i feel completely guilty because i still think it's gross, i just wanted to make him happy. I've even gone to the extent of making him promise to NEVER tell anyone, even his best friend and we vowed to never do it again. i just need some kind of help 😩😩