Having Sex in the 11th dimension.
Usually involves Supergravity and M-theory. This results in having sex with your lover of choice, then ending up with your grandmother
46 years ago, then in a different galaxy, and finally you inexplicably become a tentacle
monster that, for some reason, looks
like a deviation of George W. Bush.
As you drift into eternity, screaming every known and unknown language, you question why you bothered to look past 4th base. You become insane.
Then you Die.
...In other
words, a fun time. =D