What makes a man want to be pegged?

I have a new guy I’m interested in, he’s in his 50’s. He’s told me the things he’s in to, for example, he wants to be pegged, but not just pegged, raped by a woman. 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 also says he masterbates and 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. Is this just BDSM?