Portia, It appears that you are really conflicted about it and when people are this way, we suggest that you do nothing, sit quietly and the answers will come.
Me, personally, I wouldn't do the song. He's got last year's on his phone and he can replay that one if he needs to have one sung to him. You sent a card and that is enough. His ow can sing to him till the cows come home. The only way he will miss you and the things that you did for him is when you are not around. I wouldn't hold myself as an emotional hostage over this song...he may opt not to get together anyway. If your "friendship" truly means anything to him at all, he will not continue to bug you about the song and he will keep the plans that the two of you have made.
As for filling an emotional void for him...stop his cake eating. You are not his mother or shrink and he needs to learn to appreciate and have respect for you. Take back your respect and let this man go and find himself. He's definitely been straddling the fence and if his lips move, he's lying to you about the ow. The affair will not die a natural death until you set him completely free and she gets to hear all of the bloody, gory details of his life. Why should she only get the best part of the cake and you get the scraps?
Let him go, let God have him for a while.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
