You are a much more patient woman than me. After those few songs he would have had a lot of explaining to do and a choice to make. Been in that situation before, He tried to play the injured party - why are you invading my privacy and checking up on me? I did not play that. BTW the just for "shits and giggles" excuse does not fly either.

You teach people how to treat you. If he is in a relationship with you that means he stops looking for something better - no negotiation, no discussion. Let it go now and you will battle this for the rest of your relationship.