Did you ever notice that the first shot in GTA IV with the guy in a bondage suit screaming "Daddy's back you bitches!" is supposed to be a reference to the Hot Coffee mod of GTA: SA? It's not exactly the same, but the fact that it's a hardcore act and that it's literally the first shot in the whole game is meant to represent the fact that this was GTA's past. When Niko knocks on his door and tells him he's going to miss his chance to go ashore it's referencing the fact that GTA is leaving that kind of silly 'dildo as a weapon' stuff and will be going for a more serious story. It's also saying that it's leaving behind the Hot Coffee stuff for this game, which is funny that Rockstar acknowledges it even though it wasn't actually in GTA:SA, or wasn't meant to be.

In addition to that, the phrase, "Daddy's back you bitches!" is meant that after its leave of absence for four years and dozens of competitors trying to take its place, the real sandbox crime game is back to take its rightful place on the throne. It's meant to be GTA actually saying to the competitors that they're bitches and that daddy, the game they all took their ideas from, is back. Thought I'd just point that out for anyone who didn't notice it before. Hope you enjoyed it.