I know that "will" is used in a result clause in the first conditional. For example, If I see Mary, I will tell her. On the other hand, "would" is used in a result clause in the second conditional. For instance, If I married Mary, I would be happy. Here my question arose: If I say, "If I see Mary, I would tell her." is this sentence wrong or never used in everyday life? I'm wondering whether a mixed form of the first and second conditional is possible or not.