Yeah, well. A man can give a BJ to a woman if
1. She is a trans woman who haven't follow a surgery.
2. She wears a strapon
But the heteronormative society usually would assume that is a woman role's. So much to discover.
It’s not like they’re already in to SM and are pros or anything. We couldn’t expect them to know the BDSM terminology in detail. It’s the first time they’ve seen such porn and trying it out. I’m guessing they probably only have that kind of tendency but not like the real thing, so even if they did role plays it would be just normal sex that’s SM-ish, if you know what I mean.
THERE IS NO WOMAN ROLE IN BDSM! !!! You have a Dom and a sub/Master and Slave - Regardless the gender.