would it have made any difference to the curse if mary margarey and david stayed together atau not?

the thing is that they kissed mulitple times but the curse didnt break then. that could have something to do with that their being together was unfaithful cause of david's marriage to kathryn. my soalan is is that has mary margaret's and david's being together at least help weaken the curse? it was really emma's Cinta for henry that broke the curse