What makes a man want to be pegged by a woman?

I have a new guy I’m interested in, he’s in his 50’s and has apparently been into the idea of being pegged by a woman, but never had a partner willing to do it for him really. He wants to be pegged, but not just pegged, raped by a woman, with a very large strap on. Now I think he’s probably in to me because I’m confident and take charge. This is a new arena for me tho. He says a woman tried it on him once but then she wasn’t interested in doing it again. He also claims that when he masterbates, he uses penis pumps and electric shock and ties himself up(still trying to figure out the logistics of that). I’m willing to explore his desire for him, but just wanted to know if anybody could give me a little insight into why this might be his kink? I get that the man’s G spot is in the rectum, but what is the, being raped with a large strap on by a woman, offer? I’m not trying to judge him, I just want to know where this kink comes from, if anybody can chime in.