Dating Younger

I'm gonna be turning 40 this year and my bf is 25. Weve been together for over 6 months and our relationship is growing stronger by day. I am generally young spirited but sometimes I find myself not wanting to do things like going out, staying up late, doing large groups activities, but instead opt in for intimate dinners with close groups of friends, staying home and watching a movie, ect. I feel like he wants to do more adventurous, last minute things but I usually don't wanna do anything unless it's planned. I don't wanna come off as boring old man, but I don't like spending time with large crowds and with people I don't know. Anyone else is dating Younger and experiencing similar things? If so, how are you handling it?