This is going to seem like a real non problem. I just need somewhere to process it I think.
A few years ago, I met a man who was much younger than me but we really liked each other. Nothing happened because of the age difference.
A few months ago, we became reacquainted and began seeing each other casually. It really isn't anything serious. We chat everyday by text and probably get together once a fortnight. He initiates the texts. I think that 'good morning' and 'good evening' texts are something that maybe younger people expect due to the 'constant contact' aspect of phones now and SM or whatever but I find it intrusive and boring tbh.
The thing is, I've just lost interest.
We went away overnight together at the weekend - he invited me and paid for the accommodation and meal, I drove and covered fuel costs. The problem is that I've just completely lost interest in him on the back of it.
The age difference felt very obvious. I felt very self conscious being seen with him. Spending that much time together really exposed how we have nothing in common (beyond the sex 🙈) At the end of the evening he told me how many other girls were looking at him on the night out and how their boyfriends looked pissed off and made a few comments that just irritated me a bit.
The comments about other girls looking at him don't bother me. Firstly, they were and secondly we're not in this for the long term and I liked him but don't have feelings for him. So I wasn't jealous, I just found it boring. Maybe when I was mid twenties I also cared about how many men looked at me on a night out? I can't remember! 
I assumed that he'd have picked up on all of this too but he's still been in touch this week and yesterday told me he has a surprise for me.at the weekend. We don't have plans to meet, he's just coming round to drop 'a treat' off for me. He's also made references to the 'next time' we go away together. But I also know he's not in this for the long term so I suspect he was saying it because its what 'girls like to hear' rather than because he actually wants to.
Do I need to break it off with him face to face? All I really want to say is that the age difference is too much for me, even for a casual thing. I just need and want some time on my own. It's been fun but I just don't want to do it anymore.