An activity or event that is totally despicable.
1) It could be a conversation you have with your mates about something weird
2) It could be the fact that someone is getting away with something that they shouldn't.
3) (First used when two boys (JR, BA) were playing NBA Live 2003 on playstation in Queensland, Australia.)
HM: It is cool to dump a bog in the shower
me: mate, this (conversation) is a sickfest
LOSER: hey man i'm two-timing these two really hot chicks
me: mate that is sickfest
BA: Haha JR I'm beating you even though I've never played this before
JR (me): this game is a sickfest