bunga bunga is mainly sex, very active sex
Bunga bunga words derive from an italian joke. 3 white men in an expedition are captured in Africa by a cannibal tribe. The chief tells each one separately: ' You will die, or you will get our bunga bunga (forced anal intercourse is implied).' The first 2 say they would choose bunga bunga instead of death. The third, being the chief of the expedition, thinks he as dignity to preserve and says he will rather choose death.
The tribe chief says, I admire and respect your decision, but, anyway, let's do some bunga bunga first!