It's possible, due to the extreme reaction you had that was probably a result of you feeling "abandoned" by him.

Had you reacted in this way because you felt he was making a gigantic mistake (perhaps she's abusive or using him for the family's inheritance, etc.) then your reaction may somewhat be reasonable and selfless. Your reaction, however, was to do with your own personal loss on a situation we ought to be happy for (a wedding, a birth, a graduation..).

Of course it's sad when our relationships change. Like you've mentioned, your brother getting married, or a new SO taking our best friend's time away from us. However, we can quickly move forward without this excessive reaction, knowing that they will still be our family member or best friend, regardless, and not internalize it as abandonment.

Just my opinion.