“Six“ refers to behind you; your backside. Dining in the six refers to putting your mouth on someone’s anus. Thus “riding in the six” refers to anal sex
On the The Colbert Report (a show on Comedy Central at 11:30) episode "Wikiality", host Stephen Colbert asked viewers to add this sentence to Wikipedia, on the basis of wikiality, which means that if most people believe something to be true, then it becomes a fact. It can also be used randomly or as a joke.
six flags in the bedroom is when a man has many techniques during sex and will always pleasure anyone in the bed with him, if you meat a guy like this he will confuse you at first but really hit it off and you will probably want to stay with this man just because of his sex.
Johnny Threefingers: "Heard you're getting out of this craphole today."
Harry Hophead: "Pfft...well, I'll be back...you know me, man... ""I’ll be out the gate by eight / in the spoon by noon / fixed by six / and back in the pen by ten!”"