I need advice girls

So here goes, I've recently started talking to one of my guys friends (he started talking to me) and I noticed I had sparked up feelings for him again, we were kind of together a long time ago but I ended things, I was young and stupid, so anyways the thing is he had recently been through a break up when we started talking and today I saw him again in person and my heart fluttered, so I got all excited and I thought I'd try my luck, I must've obviously walked under a ladder tho because him and his ex are talking things out tomorrow and I don't know if I should tell him how I feel or just let him get back with this girl {back story, she left him because she "didn't feel the same" with him anymore} the last message I sent him tonight was that he must let me know how things go and that I don't want him get hurt again, should I tell him about my feelings or just let him go