I can bottom for my wife now and then. She uses a Realdoe with a Rodeoh brief. I have bottomed for a couple guys over the years. Although the feeling is really good, and the experience is really hot, I can't do it with guys any longer. For me, my head gets in the way. Bottoming for me is more submissive than my personality presents. Being at the hands of a man like that, you give up any control. I totally get why so many guys love it and I wish I could get over what I can only define as homophobia.
Concerning topping...when it comes to giving anal sex, I am 'by request only', and even then I have to be really worked up. I never ask for it. Again, this is a conditioned response. Too many horrible experiences from inconsiderate assholes, literally. I never understood the attraction for anal sex, other than control. To me it's pushing away a porterhouse in favor of a burnt hot dog. Once anal sex starts, that's where it's ending without a trip to the shower. I dislike that kind of break during sex. If I am seeing a guy, it's just for oral sex on my part. I have tried to top the last couple guys we saw but even if the heart is willing, willie aint willing.