Cheating, a slightly diffrent prespective

Well imagine this scenario:

Lets say you are at a party, your with your girlfriend/boyfriend and you meet another couple, well lets say things start to go well between you and someone else’s boyfriend/girlfriend and its obvious that both of you are attracted to each other. So you start it off very well. So now you think that there might be more in to this than your current relationship. So it is okay to try out where this goes, or should they stay fateful despite the obvious better relations that *might *come out of this, should they take the risk and is it okay to do so? I mean, if a better relation ship might come out of it.

I understand, that it can be just a feeling for the moment of a better relation ship, but lets that it looks promising.

Is it okay.