A couple of other things:

KY Yours and Mine - that's a thing

Finally, you have to both be okay with this, but **** sex can often drive a guy over the top. However, I would strongly suggest that you follow a couple of Webgoji's rules if you go to this point.
1. Be gentle! Seriously, or she should turn around slap you upside the head.
2. Don't ever ask your partner to do something you wouldn't do. So if you both consider **** sex, then you should be ready for her to turn around and stick something up your rear.