My oldest Daughter has been in these situations twice and is married to a man that has 2 step daughters and a son he raised. I tell her she also had two sons when she met the last man, this man adopted one of her sons and treat both young men as his own. I told her she must do the same. Admit for whatever reason you and Hubby wasn't together at that time and you both did whatever. I don't think it would be right to deny either of them contact with each other. If you do you will only cause yourself to look bad. just my opinion and that is what you asked for, opinions.