Boys at my school called ‘gay’ for holding hands. Girls being called nothing for hugging and cuddling.

Recently, my class had a bonding activity that required you to hold hands. And in my school, holding hands is a BIG thing. So what happened was that a couple of boys were holding hands, and for the next few days they were teased and named, ‘gays’. It is funny and all that shit, but the girls were hugging and cuddling and all that shit, but they weren’t teased or anything. To add on, the group of boys told the principal, and our principal told them to ‘man up’ and ‘get over it’. What the shit is going on? Why is this thing going on?