the act of having intercourse in a pool or lake and when finished drowning the partner for fun
Alex- what did u do last night?

Jack- water monstered this prostitute in wyoming.

Alex- YOUR A SICK MAN!

Christi- ughhh last night was so lame!
Laura- why?
Christi- Jack thought it would be funny to water monster me but he decieded not too after i almost died.
Laura- what a jerk!
Christi- but its ok i seduced him into some sloppy seconds and water monstered that asshole myself
by pinkdinosteez September 4, 2009
Get the Water Monster mug.