I'm afraid I agree with your boyfriend's therapist. He should have kept this to himself and put it in the past. You met him in July, 2023. Five months later, while he was far away, he had a one night stand. I personally feel that you are making way, way, way more of this than it deserves. This young man and you, both, have boundary problems. Even people who are dating and think they're in love need to have some boundaries. You have this idea that, in a relationship, there should be absolutely no secrets. IMHO, that's just not true. You seem to want him and you to be merged into one identity. That's wrong, IMO. You are two separate individuals. You each need to have a zone of privacy. You each need some boundaries. The idea that he must make himself an open book to you and totally bare his soul to you about everything and anything is depriving him of any dignity as an autonomous being. This young man has no filter and no boundaries. He sounds like a guy who grew up with a very domineering parent who stripped him of any sense of being the owner of himself. Someone turned him into a passive man who needs to be ruled by someone else because he has no sense of how to run his own show. That girl he went to the hotel with was probably running things when he was with her. Now he wants you to take the reins and rule over him, like his mother or his father did. Is that what you want in a man?

You and your boyfriend sound like two decent, nice people who have some growing up to do. He needs to realize that, sometimes, the best thing to do is to shut up. Not everything should be shared. You need to ask yourself whether you really want to be interogating him like you're the police. Naturally, you're hurt. I would be too, if I were you. But I would not be making such a huge, big deal out of this. It would be a big deal, if this was part of a larger pattern, where he was a skirt-chaser, looking to jump into bed with any female who will have him. He doesn't sound like that kind of a guy. As you say, he's inexperienced with girls and with people in general. I would advise you to let this relationship continue, if you are still in love with him. I wouldn't end it over this one confession, which he was foolish to ever make.

No wonder this guy is so prone to depression. Someone smothered him, when he was growing up, and now you are smothering him. He locks himself in a room because it's the only way he can keep others from crowding him emotionally. He is way too open. He uses a bedroom door to take the place of the normal boundaries he failed to develop because he was not allowed to have boundaries as a child. He believes that in a loving relationship, he must give the other person complete access to every thought he has and every move he makes. You also seem to believe that. You are both wrong. Dating someone for 5 months does not give you that right.

I'm not saying I approve of infidelity. But let's look at the context: You two are not married. You don't even live together. This is a period of getting to know each other, which takes more than 5 months. It takes more than a year and a half. If you have enjoyed being his girlfriend over the past 10 months, then I would not throw that away over what happened in Dec, '23.