You'll play what by ear? Getting together in person?
To me, "We'll play it by ear," "We'll see," etc. usually means a postponed no. It's what I say when my daughter asks if we can go to Six Flags this weekend, even though it's 850 degrees outside, or when my wife asks if I want to go along for a week-long visit to her mother. The answer will be no, but I'm putting it off because I don't feel like dealing with the objections or arguments at that moment.
In your case, it means that he's not ready to meet you yet, or he'd jump at the chance. I don't know how long you've talking to this guy, or how far apart you two are, but both make a difference. If it's only been a few weeks or he lives far away, then it's understandable if he's not quite ready for a face-to-face meeting. Flights are expensive, and no one wants to travel across the country and be stuck with someone they don't like in person. If you've been talking for months and/or he lives nearby and still doesn't want to meet, I doubt he ever will.
Proceed accordingly.
Or he's married or otherwise involved.
When you talk to him is just whenever, or is it scheduled?
If it's scheduled he just likes the attention and most likely justifies his actions by keeping things on the phone and computer because then it "isn't real."
Either way you're getting strung along, ditch him and move on.
My sons learned very early on that whenever I said, "We'll see," that it almost always ended up meaning, "No." I agree that that sounds like what is happening here.
Can also come in the guise of "hard to say".
Isn't that one of the Magic 8-Ball answers?
What a lovely day for a 3322653! SCK was here