Questions about dating an older man

I recently started dating a guy who is 15 years older than me. I'm 22 and he is 37, we will call him John. Well the first time we met we grabbed something to eat, went back to his house, watched a movie and hooked up. Afterwards we talked for awhile. John told me that he's a construction worker and works specifically with concrete, is divorced and has 2 kids. His kids were with their mom attending a funeral for a few days. I didn't really ask much about his family because we had just met and I didn't want to pry.Well we continued talking and 2 days later we went on a date. We had a great time and I felt like we were really connecting. The next night I came over pretty late due to work and stayed the night, his kids were coming back later that afternoon. Turns out they arrived earlier than expected.John wasn't out to anyone yet, which is understandable seeing as he was married for so long and those types of things are hard to explain to kids. Well when they walked up the driveway i peeked out the window and it turns out his kids weren't kids, but basically adults. He got dressed in a hurry, kissed me goodbye and told me he was gonna take them to get something to eat and he would text me later. John later told me his son is 19 and daughter is 17.I don't know how to feel. I wished I would have asked more about his kids so I would have been prepared but I never even asked what their ages were. His kids are basically the same age as I am. I found out that his son was at the same high school with me! He told me if it freaks me out I don't have to continue our relationship but I actually really like him. He is everything I like physically (I like my men rugged, bearded and muscular) and he's also funny, sarcastic and has an amazing personality. I haven't seen him in a few days but we still text. I'm just having a hard time accepting that his kids are around the same age as me.Thank you for reading and any advice would be appreciate.