Off To Town

My son had several friends over on the weekend and I had to take him and several of his friends to town so he could pickup his car. There wasn’t room for one of his friends so he had to stay behind .
We have a little guess house, and just before i left I setup a Game camera in there to see if his friend would be responsible respectful 18 year old.
To my Surprise, I see my gf , tall, tanned hot beautiful woman and my sons friend come in there, they are cleaning up, then take out a bong, smoke a bowel, then 15 minutes later, they start making out, they both strip I thought they were going to fuck but she sucks his cock off, I see his cum blast all over her. Wow.
What a lucky young guy. I can’t seem to be mad at either of them, is that crazy. What to do?