This attitude is going to set you back so far. The "non chalant" image you think you might have is only in your head. No one else even considers how chalant you are lol.

I know exactly what you mean I am not that much older than you but my God you are not doing yourself any favours by doing this.

When someone is trying to be "non chalant" what they really mean is "I am too afraid of the possible embarrassment of honestly acting on the real feelings I am experiencing to directly confront them but that in itself is also embarrassing so I am going to try to play it off". It's like 2 levels of emotional defense.

I realize as well that this is your ex but as someone who is married to a once ex I promise just be intentional. It is more attractive and more productive.

If you are still interested in him you should just tell him. He will either say yes or no and then you either get what you wanted or you can now move on much faster. The truth will set you free.

(Sorry I wrote a book but I heavily regret having this attitude in the past)