Note: this only works if your girlfriend wears contacts.
Instead of coming on her face, you come in her contact lenses case, make her put her contacts in the solution, wait the full eight-hour cycle, and then put them on, resulting in stinging and your personal satisfaction.
Man 1: Guess what I did last night?
Bro 2: What?
Man 1: I gave me girl the ol' pearl vision.
Bro 2: Man that's a double entendre!