My boyfriend came in me for the first time a couple days ago and it kind of burned a little bit the first time he did it? We're both clean so I know it's not an STI. We didn't really do a lot of foreplay before sex but it didn't exactly hurt me until we did a second round. After the first time it wasn't bad, but I had to make him get some lube for the last three rounds out of five after because the actual sex was starting to hurt a little and not in a good way . After we were done, I rinsed out most of the cum and took a bath since I was a little sore and all pain disappeared within an hour of us stopping and never came back.

Does it seem more like I just wasn't wet enough at the beginning that lead to a minor tear or something else?

I have considered whether I might be negatively reacting to his cum since I've gotten sore throats when giving him a BJ but I'm not sure if that's just my throat not liking it or if I'm actually having a reaction to it.