Whilst two males and two females are performing the Tower Bridge, both males forcefully thrust inward simultaneously during climax causing the females to smash their faces together, which in turn, causes them to fall, effectivley collapsing the Tower Bridge.
Andy to Matt: Paul and I were totally Tower Bridging those two chicks from the bar last night...
Paul to Matt: Yea man, we had it going good until the Tower Bridge Collapsed...thoses bitches were pissed!!
Andy: Ahhhh they're fine, I gave them ice packs afterwards!