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2 guys having sex with one girl. One from the front, orally, one from behind. Guys can hold hands, so the tower bridge is complete
I had a threesome, mmf. A perfect tower bridge
by gijs-jan January 23, 2009
An extension of the eiffel tower, with the addition of one female. The girls face each other on all fours whilst kissing. Simultaneously, the males are plowing the females from behind and touch hands above the females, resembling the Tower Bridge in London.
Guy 1: Dude, check out those two hot chicks at the bar.

Guy 2: Don't even think about it bro, me and Sam pulled the ole Tower Bridge on them last week.
by rdk236 November 30, 2010