Boyfriend Wants Anal

I've been having sex for a bit over a year, started when I was 20. I liked it with my boyfriend at the time, it was good, and after he broke up with me, because I "wasn't any good" at sex, I was feeling like shit. So I went out and at a bar, let 7 different guys fuck me, and I sucked them all to hardness. I did have 2 other guys for about a month each before they broke up with me.

I'm a very petite woman, size 2, only 5ft. 3in tall weigh 105lbs when I've put on weight. The thing is my boobs are very small also, not quite totally flat but really small but super sensitive, my hips are small and my outer lips are tiny. I don't know how to say it so I'm just going to say it - my outer pussy lips are only an inch and a half long, but my vagina is normal sized so I don't have trouble taking a man.

I was a bit hesitant when I finally got with my current boyfriend. He is very thick, the thickest I've ever seen. He stretched me a lot and sex was very uncomfortable for several weeks. Now I can take it no problem. I do have a problem trying to suck him hard though. I have also let him cum in my mouth, at his insistence - I'm not a fan. But putting my mouth around it totally is too much. I pretty much lick it all over, put my mouth over the hole and use my hand when I do it. Now in my vag it's fine. He has commented on how I do just lay back and don't "fuck back" at him. So I've tried to change my ways, but when I do he bottoms out in my vagina and it hurts.

He says he'll stay if I let him do anal sex. I'm going to let him this weekend, but I have made him promise to go super slow. I'm still not sure I can take that thick thing in my very small bottom hole.