Did I overreact

My fiancé and I are going to disney world. On the way my fiancé wants us to stop in Savannah Georgia so I can meet some of his family that lives there. We are driving from Ohio. He says it’s also a beautiful town that we could have a great night or two in and can stay at a hotel. However I’m pissed that he wants to take time away from our vacation to visit his aunt/uncle. He says he wants me to meet his entire family because he feels like I am family. I told him I am absolutely not doing this and it’s unreasonable for him to expect me to. I told him I won’t even to if those are his plans. It won’t take away from any of our days at Disney but it would add on travel days. Am I overreacting?