My husband had an affair with a female co-worker.?

The affair ended, we separated and reconciled and have been going to counseling. My husband has cut off all communication between him and the other woman. My husband has a game on his cell phone called Words With Friends (virtual scrabble). I love this game and play it with several of my friends and family members. He too plays this game with his friends however he does play with one girl who happens to be the best friend of the woman he had an affair with. I am uncomfortable with this. I have tried not to let this bother me but it really does. Not because she is a woman but because she is the best friend of the woman he had affair with. It has been less than a year since the affair and less than 3 months since we reconciled. I feel he should stop playing with this woman. I just don't see how it is "nothing". I know it is a silly game. I feel like he is keeping this other woman in our lives by keeping her best friend in his life every day. There is a chat feature to Words With Friends. Neither of us uses it but he does play with this girl every day, sometimes late at night when we are in bed. Again it is NOT just because she is a woman. It is because of who this woman is and her direct connection to the affair and my marriage.