Eye Flirting and How Not to Come On too Strong

Today I was on the subway and I noticed a guy around my age sitting across from me was giving me sultry looks. At first I was flattered as I had rushed onto the train and was a bit frazzled from running for the train, finding an available seat, not to mention tired after a long day at work- and he thought I was still flirting material. After a bit of back and forth eye flirting he got off.

I then realized his gaze was different than other guys who were eye flirting- it was longer and more intense. And he didn't seem to have a bag or seem to be coming from work. Was he cruising?

Quite possibly. His gazed seemed to give hookup vibes after I thought it over. I was a bit embarrassed at entertaining him as that's not what I'm after.

This is where coming on too strongly can work against you not in your favor. A general rule I use is looking quickly (one or two seconds) 3 times to see if he does the same. If noting happens after the third time I stop. I don't tend to look at someone on the street for too long either as that makes almost anyone uncomfortable, including myself (the setting where this happens also determines the appropriateness of eye flirting) Not to mention it can be creepy if you hold your gaze for too long and do it in the wrong manner at the wrong person.

Was that the subway an appropriate setting for this man to do that? Was he an expert at eye flirting or just looking for something else? (kinda of creepy if it's the latter on a crowded subway train) I don't know and probably never will, though it did give me some more useful experience.