Don't assume girls are always pmsing when they are mad or upset. There's this thing called emotions, and it's just a fact of life.
And, when a guy shows any emotion, he is not weak. When he's crying, he's built up too much. He is not showing any signs of weakness because he is upset and bursting at the seams. Society can suck my thumb, because boys should be allowed to cry and get consoled not ridiculed.