AIO: My boyfriend (26M) of 4 years got a girl’s number to give to his friend, and I’m upset.

At a party a few days ago, my boyfriend and his friends were talking. One of them brought up this girl “Jenny” who his friend, “Dave” had been seeing until recently. They talked about how she was his first kiss/the one that he lost his virginity too. I asked for the story of how they met and my boyfriend sheepishly said that he was the one who set up Dave and Jenny.

Apparently, a year ago, my BF was invited to a dinner with his coworkers. One of them had a roommate, Jenny. She was very into my boyfriend throughout the dinner. My BF described her as a bit strange, very talkative, and bad with social cues. Towards the end of the dinner, she asked if she could give him her number, in front of everyone. My boyfriend took her number, entering it into his phone.

He swears that he never messaged her or called her afterwards, and almost forgot about the exchange. He said he took the number mainly out of pressure, and also because he wanted to set up one of his friends. A week later, he and his friends got drunk at a bar, and he gave the number to Dave, who was single/had never been in a relationship. Dave texted her that night and they went out after. Jenny allegedly didn’t seem to mind that Dave wasn’t my boyfriend. The relationship ended because she became obsessed with Dave, sending him long paragraphs and erotic poetry. Dave corroborated the story, and even showed me the things Jenny messaged him.

I was upset that my boyfriend accepted another girls number in the first place, even if they never did anything or messaged. I asked him why he didn’t tell me this after it happened, he said he thought I might take it the wrong way and decided it was simpler not to say anything.

My boyfriend took my upstairs and sincerely apologized for it, he said that he should have set better boundaries with Jenny at the dinner and told her right away that he had a girlfriend. But he assured me that he genuinely just saw it as an opportunity to set up one of his friends, since she was single and eager to find someone. Plus, he said in the context of that dinner it was easier to just go with the flow. He said I can go through his phone whenever I wanted, and he promised he will never do something like it in the future. He said he doesn’t want to brush it off because he can see how much it upset me, and said if I want to take some time to process it, he will give me space.

I’m conflicted. On one hand, yes he should have set better boundaries. On the other hand, my BF and his friends story lines up, and it genuinely sounds like my boyfriend and Jenny never contacted each other after. I do trust my boyfriend on his word. It’s a bit bizarre of a story, but this girl does seem somewhat strange.

TL;DR: My boyfriend got a girl’s number with the intention to set up his single friends. It worked. However, I’m upset at the boundary being crossed. How should I approach this going forward? Am I over reacting?