sleep stiffer
When a guy is sleeping, you rub their penis, thus getting the "stiff" and they wake up with a wonderful feeling.
"Omg I am totally gonna pull the sleep stiffer on him when I'm bored and he's still sleeping"
"Yeah last night my gf did the sleep stiffer and we fu(ked."
"Yeah last night my gf did the sleep stiffer and we fu(ked."