Am I demisexual?

So I haven’t had much sexual experience, I have met up with 4 guys and done something sexual with them(from kissing up to having sex) with all of them I have gotten on well with them, enjoyed my time hanging out with them and all lovely and nothing wrong at all but when I’ve done something sexual with them I’ve just not enjoyed it like kissing just really not into it and I feel awkward about it. After doing something sexual with 3 of these guys I just did not want to see them again, like I said before I got on with them and I haven’t got anything bad to say, no icks at all. But I just had no urge to contact them again. The only time this hasn’t been the case is with my ex, although the first time we had sex I did not enjoy it at all I still wanted to see him afterwards and was extremely enthusiastic in talking to him and seeing him again(I did start to enjoy our sex and get enthusiastic about it about 3 weeks after our first time together) I talked to my friend about this and she said that I might be demisexual. With my ex I remember at first I hated kissing, it did not turn me on at all but after a while it did? Could this be demisexuality? Now I’m just having an existential crisis