well there's the missing part to the formula - the lack of insight at the time. It is like getting carried away . Afterwards the realisation hits and the guilt or shame sets in.
Yeah I think rocking the boat maybe could be a touch of self-sabotage, you know everything is going well, so i'll be reckless.....
Its normally harder for women to have casual relationships and not realise they actually have feelings underlying, I think guys are exactly the same but they just deny theirs. That's cool if your both in it for fun.
So, to sum up - focus on that lack of insight part, could be the tipping point