I think you did a very nice thing for your son, and it does sound as if you all had a nice time at dinner. He saw his friends at an outing while you were present. That does not sound like bending rules too much to me. He just thought of himself alone. He did not bend, he broke the rules IMHO. He's fortunate that the SO did not stop by.....
Sounds like we are both marking time until Monday.
Hugs, HG