Bf Taking trip with Ex

I’ve been dating this guy for about 2 months. We’ve been friends way longer. Before we decided to date he had been trying to be more for the longest. Ever since we started dating i have to admit that I wish i would have taken him serious sooner. I’m happy with him in almost every way until recently. We’ve been having sex since we started dating. It’s great and not an issue but i feel like he thinks that he doesn’t need to make an effort to plan things for us to do. He always is busy with something and will call me when he’s done to come stay the night. Its not a issue but i’m realizing now that he always has plans but never makes plans with me. I realized that the last few things that we did where things that I suggested. Me and my friends rented a huge house for the FLA classic in Orlando this coming weekend. I asked him to come with me and he reveals that he’ll be down there already to take his step son to Seaworld with his Ex. (Ex Gfs son that he considers his son and takes care of) This whole weekend he has had his son who lives out of state and is just visiting and told me he would be busy the whole weekend. I assumed he had special things planned for him and his son to do but today found out they have just been doing normal things. Mind you he has a biological son that lives with him that i have been around countless times and have had sleepovers with his son and mine. So all in all i feel neglected. I’m trying to be understanding and don’t want to make a big thing out of it but I don’t like feeling like I’m not a priority. I don’t expect to have priority over his children at all I would however appreciate some effort and not feel like an after thought. Any Advice is welcome