He wants to be my boyfriend

I’ve been dating a man (infrequently) for about 7 months. We are not exclusive, have not had sex (or even close) and I do see other guys, but there’s no one in the picture right now that I’ve dated more than once or twice. He’s a good guy, kind and responsible. We don’t really communicate much between dates, and while I have fun when we are together I don’t feel emotionally close to him at all. He’s very attractive and in great shape but I’m only mildly attracted to him physically. I’m not one to go far sexually without REAL mind-blowing attraction AND a committed relationship.

About a month ago he started talking about sex. I explained that I don’t have sex outside of a committed relationship. He then asked why we weren’t in a committed relationship after all this time, and I explained that it may be the lack of communication between dates (which is my fault too- I’ve given him only minimal answers and tend to feel annoyed more than pleased when he texts).

Since then he won’t drop the topic of being my boyfriend in a committed relationship, but in a way that’s really off-putting since it feels like it’s mostly about sex. And my gut says no to that, so I need to say no to that. The idea of committing to him makes me sick to the stomach. I need to find the best way to explain to him that I’m not ready for a relationship with him. I haven’t broken up with him because he’s meeting my current needs just fine- but I recognize that I’m not meeting his and I’ll be fine if he chooses to move on. I just don’t know how to say it, or if I even have to until HE decides to deliver an ultimatum or end things. This isn’t a common situation for me- historically I’ve been anxiously or securely attached.