Hi Talia,
It is unlikely that you still have a chance with him.
He may have thought that he was over his ex.
This may have been why he pursued you for a while before the both of you eventually made out at his house.
However, that experience, along with his ex texting him not long after, may have made him realize that he isn’t ready to move on from her.
Yes, there may still be a part of him that feels loyal to his ex.
However, this doesn’t mean that he wouldn’t entertain having physical relations with other women.
But, as far as his emotional availability, it is simply not there at this time.
Even though his ex has moved overseas and he would be incapable of seeing her in real life on a regular basis, he could still remain emotionally attached to her.
As long as he is willing to take her calls and texts, he will continuously be influenced by her on an emotional and mental level.
This could go on for a good long while.