I don't actually remember the others telling Chase not to get back with Leo!
Yeah Leo had an extreme obsession with Chase, and that truly is bad. But I feel that Leo didn't deserve to be abandoned to the depression he went through. There had to be a way for Chase to send him a message through someone else! He could have told him they weren't good for each other and at lest needed to stay apart for a while. Although getting on the train they only had a moment, Chase really should have followed up and tried not to cause Leo so much pain! Also I really don't think Leo would have hurt Chase. Yeah he was flipping out and obsessed, but under that was real love for Chase.