How do I talk to my husband about his sisters comments toward me?

A few months ago, my SIL came down for a visit. She lives in another state from my husband and me. Long story short, when my husband wasn’t around, she was very rude to me. Some examples are like excluding me from conversations, rude comments, etc. I didn’t say anything to my husband since he doesn’t see his sister often. Fast forward to now; he wants to go up there to see her this summer. Obviously, I don’t want to go, but I don’t want to bring up his sister’s behavior a few months ago. What should I do?