Affair dilemma

My husband had an affair which his best friend knew about (he was there the night my husband and her met). after counselling etc we have stayed together but now his best friend has started following the woman on Instagram recently. I’m pissed as he knows everything that happened & saw how damaging it was to me and the kids but am I wrong? I feel like he’s disloyal to me and I don’t want him to come round for dinner etc anymore.