HELP! my boyfriend is into ass... a little TOO much

Sabrina
So me and my boyfriend have been together for 4 months. We love each other and trust each other. I am so happy there's just one problem. At the beginning of our relationship, he confessed to me that he's into ass, and you might be thinking "okay some guys prefer ass over tits that's cool." But I mean, hes asked to eat my ass and finger my ass and I just blush and shake my head. I don't know how to tell him that that's really not my thing, and that makes me uncomfortable. We've only had sex twice, and recently he suggested we try anal, which I blatantly told him I am NOT doing, and he's cool with that. Do any of you girls have his issue, where your s/o is into something that you're not into, and you don't know how to talk to them about it? Any advice for me? Part of me feels like I should just let him eat my ass once just to get it over with, and then if I don't like, tell him I don't want to do it again...