slipdogging
When a man slides his penis between his partner's buttocks cheeks, but does not penetrate. Similar to "titty-fucking," but instead involving the butt cheeks.
Brad didn't feel like penetrating, so he decided to try slipdogging instead
slipdog
Slipdog - A person (usually a guy) who always gets the bigger, better deal. Great with the opposite sex.
Dame that Del boy, he gets all the girls... wot a fuckin Slipdog