I (F24) walked in on my boyfriend (M29) masturbating to my underwear and I don’t know what to do

Throwaway account. My bf and I have been together for almost 7 months. Everything has been great, he’s very sweet and cares a lot about me, we are sexually compatible and we have been getting along great. After 3 months of dating he asked me to move in with him, and I accepted. I have been now living with him for 4 months and I’m not sure if it’s the move, or the pandemic, or maybe both, but I feel very uncomfortable after what just happened. <br><br>This morning I had to go to the store to buy some stuff. I was only gone for 15min tops, and when I came back, the house was supposed to be empty, but my boyfriend was home. I don’t know how long he has been there, but as soon as I walked through the door, I heard the tv on in his room. This isn’t weird because he usually spends hours in there playing video games and watching videos. But today I decided to walk in and surprise him and as soon as I opened the door, I saw him on the bed, watching a porn video and masturbating, but what really shocked me was that he was wearing my underwear. It was a pair of lace boyshorts that I had left in the laundry basket, and I know for sure he wasn’t wearing them when I left because I actually helped him put on his clothes this morning. <br><br>I’m not sure what to do. I don’t know if I should bring it up or not. He seemed really caught up in the moment and to be honest, I was very uncomfortable, so I quickly got out and left. I know he saw me, he looked at me as soon as he noticed me at the door, but I acted like I didn’t see anything and just got out of there. Now I’m at a friend’s place and she’s saying I should talk to him, but I don’t know how. I don’t know if I should be upset or not. I never left my underwear in plain sight before, they’re always in the laundry basket or in the washing machine. So I don’t know if this is something he’s always done or if he just decided to for a change of pace type of thing. I heard stories of men wearing a piece of clothing from their ex or current partner to feel more connected to them, but I don’t know if that’s what this is. <br><br>I just don’t know how to approach this. I don’t know if I should talk to him about it. Should I bring it up? How would you feel if you were in my shoes?