Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: So I(M27), got home today to find out my friend(M26) who has come to visit for the week(I had told him it would be better if it was less time because I couldn't get time off work) had a girl at mine and my partners(F27) place. 
He had told both me and my partner he was going out to meet a friend in the city and catch up he said he's never met this friend and he knows them from playing online games together. I was totally okay with him borrowing out keys to get back in the house incase we weren't home from work when he got back, he said he was going to catch the train out and then catch the train back home. He never once even hinted they would be at our house, someone who he's never met in person and only knows in an online presence I am not okay with.
I must add that this friend is planning on moving up to this area and staying with us for a while so while he was he we set him up in the room we plan to give to him and told him to make himself comfortable, but he does not pay rent or renters insurance and most likely won't be moving up for quite a few months.
I just need to know should I let this go. I kind of feel like he betrayed our trust but I might be overreacting. 

getting angry at my house guest inviting a stranger over while I was at work