How do I bring the subject up

I’ve known this guy since I was a freshman and he was a senior and now I am a senior and he’s in the army. We have been talking all flirty like but I’m not good at that it makes me anxious and paranoid not knowing if he likes me back and I don’t want to get to attached if he doesn’t how do I bring up the subject without making it obvious? Just in case he says it’s not me I don’t want to ruin the friendship.