There is an old saying in Poker that goes something like this:
If you sit down at the table and you can't spot the sucker in five minutes, you are the sucker.
I was out the other night with some friends and we were talking about the tendency of relationships to break up when one person or the other finds somebody outside the relationship they would rather be with. In my life I have been ditched for somebody else directly in three of three cases and did the breaking up without anyone else in my sights in one of one cases; hardly a good statistical sample size but I suspect it is pretty representative. Obviously it isn't doesn't always hold true but it is clear that a great number of relationships cruise along in 'damaged but still flying' mode and then actually end when one person discovers somebody they would rather be with instead. Of course sometimes this involves cheating beforehand but often it does not - there are no end of examples of people breaking up and then immediately hooking up without doing anything technically against the rules. That is, of course, unless you think that 'noticing somebody else is awesome' is against the rules, which I don't.
I was thinking today that you can write a saying for a relationship breaking up that sounds remarkably like the Poker saying.
If you are involved in a breakup and you aren't all set to hook up with somebody else, your partner is probably all set to hook up with somebody else.
Note in both cases there is a notion of being a sucker, in one case implied, in the other case boldly stated. People generally feel bad when their former partners hop right into another relationship and sometimes this is just because they are suspicious of what might have happened ahead of time and sometimes it is simply because they want their former partner to be heartbroken rather than relieved. I don't think that looking at it from a sucker / shark point of view is a particularly good idea though. More useful than laying blame is to just accept that people do hook up right after breaking up and that once it is over there is no point in getting twisted up over it. Not that this ideal case is going to prevent any of the usual jealousy, bitterness and regret of course... just wishful thinking.