I am not sure I understand this thinking. But it sounds like your own validation can end up invalidating someone else. That could be seen as selfish in that it doesn't consider the other person's feelings.
On the other hand, some behavior like this I have heard compared to a fear of commitment or attachment. That is "if I break it off while the guy still likes me, then he can't reject me." No one wants to be rejected or hurt.
Running away from pain or fear can only make it worse so in that case you are only validating your fear.
Some have even said that the very process of escape or running IS fear. Two good books that deal with the Buddhist approach of CONFRONTING pain and fear are "The Places that Scare You" and "When Things Fall Apart"http://www.amazon.com/Places-That-Scare-You-Fearlessness/dp/1570624097http://www.amazon.com/When-Things-Fall-Apart-Difficult/dp/1590302265/ref=pd_sim_b_njs_title_1
One more thing about Karma. The notion is not so much that you are being punished by external forces, but that you are punishing yourself when you do bad things to others. You are perpetuating your own suffering, like spinning a wheel until it rolls up and then back down on you.