Backstory: I had my son when I was 17. His father was never really in the picture, so I was a single mother for the most part. Now I'm 38 and my son "Ben" is 21. He's been suffering from depression the past couple of years. I take him to therapy every week and he seems to be getting better but he's always been an introverted kid, so he seems lonely most days. When he was in high school, he was in a band but that quickly disbanded after one of the members graduated high school and went off to college. I recently made a suggestion for him to maybe start up a band again. To my surprise, he was excited about the idea but didn't really know where to start. I suggested he make posters to advertise and maybe place them around his campus. He got to work right away and showed me a flyer he had made. I asked if he wanted me to put it up on the bulletin board at my work place and he agreed.

As I was posting up the flyer on the board the next day, a colleague "Joe" walked up beside me and noticed the flyer (he's 29). I never really talked to Joe in the past because we work in different departments but I recognized his face and knew of him through other colleagues. We started talking about the band and Joe said he sings and plays his guitar every now and then. I told him he should audition and we both laughed about it, but toward the end of our conversation, he seemed interested, so I ripped off the part of the flyer that had Ben's phone number and gave it to him in case he wanted more information.

Long story short, he audition and ended up in the band. The band consists of Ben, Joe, and two other people (both go to school with Ben). I'll admit, it was weird having Joe over at our place at first because we were colleagues and never hung out outside of work or work events, but I didn't mind it because Ben seemed happy and talks a lot about Joe (the two hang out often).

A week ago, Joe was supposed to come over and work on some lyrics with Ben, but Ben was running late, so I invited Joe inside for a cup of coffee. We started chatting about work and complaining about our supervisors to each other, which was really nice to do because I haven't been able to vent to any of my other colleagues about work stress. We talked about the band and he played a sample of a song they were working on, which sounded similar to a song I had heard before but couldn't remember the name of. He asked for my number so that I could send him the song if I ended up remembering. I sent him the song that night and we've been texting all week since then. I enjoy talking to him a lot and it honestly feels like a stupid high school crush (I haven't seriously dated anyone since I was with Ben's father). Yesterday Ben found out I'd been texting Joe and got upset, saying that it's weird and that I can't date his friend. He compared it to "what if you dated Matt" (his 21 yr old friend since middle school). I don't think it's the same situation though. AITA?