The most convenient moment for a man to take his socks off before engaging in sex. If the Sock Gap is missed, then the man will end up naked except for his socks, which will ruin the mood.
The Sock Gap is rumored to happen some time in between removing the man's shoes and removing the man's trousers.
Coined from the British sitcom "Coupling."
Guy 1: So how did it go with Jenny last night?
Guy 2: It didn't. I missed the Sock Gap, she couldn't stop laughing.
Guy 1: Bummer.