An acronym designed for when either: 1- Something is superficially very amusing but actually quite depressing; or 2- Someone finds something which would ordinarily be quite tragic to be unreasonably amusing and wants to give the impression that they aren't totally soulless.
Jill: Damn,... lotocoti... (Jill actually has AIDS)
2. Jill: So last weekend I was skydiving with my bff Jan, and her chute didn't open!
Jack: ROFL... err my bad, lotocoti!