Usain Bolt -- INSANELY DIRTY DANCING ... Pre-Carnival in Trinidad

Here's video of Olympic god Usain Bolt jack-hammering away on a lady friend in Trinidad during an erotic dance session in Trinidad the week BEFORE Carinval.

The dance is called "Daggering" ... for obvious reasons ... he's pretend-stabbing away like he's Brutus and she's Julius Caesar.

For the record, this type is dancing is par for the course at Carnival ... and the party never stops.

Just ask Jonathan and Jordan Babineaux ... who went to Carnival in Trinidad this year and admitted it kicked their ass.

Bolt doesn't seem to have that problem.