Nut cream is a complicated sexual act which probably will become popular in porn movies very soon.
1. You (the man) fucks a girl in the ass and cum on her asshole (note: not in her asshole).
2. When the sperm lies there on her ass you take a hold off your balls (hence the term "nut") and puts 'em down her asshole, then begin to "ballfuck" her.
3. Take out your balls, now dripping of sperm and "brown sauce" and let the girl take a lick (or suck).
This is what you call "nut cream".
- Hey girl, wanna take a load of nut cream?
- Hell yeah, let me lick it off!