I would definitely, definitely not text him - do something else. If he is seriously considering going back to his ex then you are wasting your time. At least he has been honest about it. I would say that if he doesn't get in touch then he has got back with his ex and will end up just ignoring you which will hurt more. Leave the ball in his court. If it is meant to be it will work out. PS: You say it's just sex - how long have you been sleeping with him?