men can"t take being alone it drives them crazy!!
i know several men, who say that when they knew their relationship started to go down..they started looking for a "side junt"..and would keep her on hold ( ie: show her just enough attention...and string her along) just in case things didn't work out in their current relationship.
then if the current relationship..went to hell..they didn't miss a beat..they had another woman ready, willing and able..who was happy to have him!
i was also told that they wouldn't try as hard with the current relationship..because they knew they had a back-up.
these are their words exactly...i'm not saying all men do this..but quite a few do.