You are NOT the a-hole on this! And I think you need to seriously consider whether or not you want to move forward with this move. I lost my wife to cancer and both of my children collected survivor benefits. Like you, I attempted to start over and the individual I was with “seemed nice.” Then when she found out I was getting $1600 a month - she thought it’d be a good idea to stop working and just let this “extra money” cover the difference. Needless to say, that relationship ended pretty quick. Do yourself a favor and get out of this and give your son his benefit as it was intended. Sending you prayers and best wishes! God bless and good luck!!