It's the ass that seems to attract the guy the most. Once he's tried it, he won't want to deny himself anal pleasure anymore. A girl has a chance to offer him MJM to fill both holes. And if you offer it to a guy during sex, he'll agree to anything. I'd love to hold on to those little tits and cum on them.
I, too, would have joined in the brother-sister game and inserted my bolt into the girl's tight mink. It makes my cheekbones crawl with pleasure imagining it!