I can understand why gay men or men who are into men like it, as it's the only orifice you can penetrate in a man.

But what's the appeal of anal sex in straight sex?

I have heard and read about so many husbands/boyfriends who are secretly disappointed/resentful towards their wives/gfs for denying them anal sex.

It can be really painful for women. Unlike men, we don't have prostrates and nothing in that part of the body can be stimulated.

I have heard about men in LTR/marriage, stable, happy ones at that, go to prostitutes to get anal sex.

Funnily, many such men who desperately want anal sex from their women would absolutely turn down any requests of pegging from their partner.

If the idea of pegging is uncomfortable for you (and it's okay if it is), then you have no right to be bitter towards about a partner who is against anyone coming into her backdoor.