What a perfect expression for so many of the Russo-Ukro-Eastie group out of NYC, whose handler promises clients anything or everything and the poor straight guys are too uncomfortable to deliver if they even get that far.
Urban Dictionary:
Drop the mic
To give a guy a handjob, but during the handjob make it awkward, but not so awkward that he doesn't want you to finish. Make it very impersonal and then right before he's about to cum let go of his dick and walk away.