Was I wrong for bringing this up?

So before I tell you the “story,” my boyfriend and I never really discussed boundaries with each other. It was more of like a “you should know” type of situation.

Yesterday, an old classmate who is a guy just came back from Miami from an internship. It was my first time seeing him in forever so we started talking before I headed into class. He asked me if I and our other classmate (who is also a guy) could meet up and grab some lunch. Without thinking I thought it would be a cool idea to get together as a group.

So I brought it up to my boyfriend and he looked at me as if I was dumb for even bringing this conversation up to him. He said that it sounds wrong and disrespectful for my classmate to ask me to go out with him and my other classmate.

So now I feel like shit but at the same time I don’t because I brought this to his attention before going.

Was I wrong for bringing this up to my boyfriend?