Am I in the wrong??

My boyfriend and I live in two diff states. I just so happen to live in the same state as his mom and she lives about 15 mins away from me . I just recently met her about two months ago and she really seemed to like me . She suggested that we go do a paint nite because she always wanted to and I thought it was fine. I set up the event, I told my boyfriend multiple times and each time he gave me grief, I thought he was just kidding. Last night I reminded him that the event was today and he got super irritated QUICK. He said he feels as if I'm rushing things, by hanging out with her. 1) I really don't see the issue if its something HIS mom suggested, I didn't suggest to her , 2) I don't see the big deal if the direction we're heading in is marriage, he should want his mom to like me, right??? We've been dating for a little over a year now, and a little less than half of it has been long distance. I told him it wasn't gonna be something that happened often but he was still pretty upset. Am I wrong for wanting to build that relationship with his mom or is he trippin?