Being together for better or worse?

My husband kisses my best friend who is married 3 years ago. they had more of a make out i should say which I recently found out about. when i remember being with him, he's given her the longest hugs, even when she pushes him away, he keeps lingering on to her...infront of me. we can be watching tv and then he'll sit across from me and her, but his eyes are gazed upon her...he is not watchint tv or me. also when we have parties, he is 90% of the time listening and observing her. as far as I have seen lately, he has had some tension around her in that if he says something like he can't be with her or he can't do something, it makes her upset and then he is all trying to saw sorry, he will give her long hugs to make up for it, and then he cares when she gets upset. so why does he say no to her and then care about her feelings all the time in more ways than one, even if I am present or not? I mean based on just me, i see that my hub loves me alot, he gives me presents and takes me to vacations and always does sweet things and compliments me...i am nto sure? Is his caring for her moods and feelings like that an indication that he loves her or is he playing her?