Dog Impounder

entering into a dead-end relationship with a cheating/unfaithful guy; treat him like a pet until he becomes too emotionally attached; allowing him to stray as he pleases, knowing he will find his way right back to you...

A girl who deals with an unfaithful/cheating guy who has made it clear that he's not leaving his wife/main girl; but you take him in, giving him special treatment like a pet, causing him to become emotionally attached (Dog Impounder). If he strays away, you know he is too caught up to leave & will always keep coming back...