when a girl is fucking you while she has a yeast infection and smears that goop all over your shit.
yo i ran into some lap butter the other night, it was horrible.
by DonSlappy November 02, 2011
a clear yet cloudy liquid of great viscosity, that is excreated from the lap of a suitably excited woman.
her lapbutter made his knee very difficult to balance on, the floor was also covered.
by stoph1983 April 28, 2007