Savian's Roulette
When a man rams his dick at the small bit of flesh between the vagina and butthole with a 50/50 percent chance of "sliding" it in either.
Man: Can I lube up your gooch tonight and go a few round of "Savian's Roulette" for old times sake?
Girl: Of course you can, I always enjoy it so much ;)
Girl: Of course you can, I always enjoy it so much ;)