Making out and blue balls ?

I’m pretty sexually inexperienced so hoping someone can help me out here.

During and after making out with this guy I’m seeing, he keeps sighing, fighting to not take things further. Like for instance we are against the car making out and he does that, then we get in the car and he just sits there for a minute and looks like he is composing himself. Is this the whole blue balls thing? Is he like in emotional or physical pain?

I know I don’t owe him anything and its going to be up to me what I want to do with him but trying to understand what he is feeling in those moments. I get wet when making out but not an intense desire to go further.