Why is my stepfather feeling uncomfortable

Does my stepfather want something from me? Urgently need advice

Hello! I am currently 18 years old and still live at home. My mother has been separated from my father for 15 years and has had few relationships since then. Now she recently met a man again through her best friend. He lives about 1.5 hours away from us. At the first meeting we all went away for the weekend with a few friends and I have to say that this man made a very good first impression. He was really nice and friendly, also helped with the cooking and I got on very well with him straight away. Anyway, after that meeting, he and my mother swapped numbers. Then you also wrote for a while. He got in touch with her almost every day. However, he then got a WhatsApp message that he did not want to disappoint her and that friendship would be ok for him. Anyway, my mother and I met him again at a barbecue in the house of my mother's best friend. We celebrated my 18th birthday there and it was there that I noticed for the first time that he was acting strangely towards me. He smiled and grinned strangely at me almost the whole evening. It wasn't a normal smile, but rather reminded me of two boys from earlier times who were once in love with me. I found this constant smile very uncomfortable. When my mother told me in the course of the evening about my neighbor boy who was madly in love with me, he said that if he were my age, he would love me too. I also can't tell whether it was meant seriously or just for fun. He also wanted to sit next to me the whole time. At least when we were alone for a short time later, he told me how sad it was that I had only helped in the kitchen for an hour (the party was from 7-3pm) and we had no time at all to entertain, although my mother and I sat at his table from 8 to 3 in the morning. Then he also wanted my cell phone number and that I send him a photo of the party. When I said goodbye to him alone with a hug, he then quietly said "Good night, beautiful" in my ear. The hug also felt kind of strange and like "more". Since that party he has been in touch with my mother and writing things like, "Good morning you two". I don't know, I find that kind of strange. I have a very bad feeling somehow. He behaves completely differently than my mother's previous ex-boyfriends. I can't tell if he just wants to be nice to me. But in contrast to the first meeting, I feel very uncomfortable in his presence. I don't really know what to do now either. If he really means all of this nicely and as a compliment, I would probably do him a very grave injustice if I asked my mother or her best friend (my godmother) about it. As far as I know them, the two would immediately kick him out of the circle of friends and tell the whole story, regardless of whether my assessment is the truth. I've already talked to my best friends about it and they recommended that I talk to this man about it alone. However, he lives 100 km away from me and I would also not feel comfortable meeting with him alone to talk to him about it. I also don't know who else I could get help from or who could help me with a conversation with my mother. Unfortunately, I no longer have any close relatives.