Telling OP grades to another student (his son in this case) is a serious thing in some countries.

If he told your friend about your grades, that is illegal. Teachers and professors are not supposed to give out a student's grades.

I had an aunt and uncle with the same mentality. During the height of my depression I had somehow managed to keep above 90s but brought home a math test with an 82% on it. They proceeded to berate me, asking me if I deserved 80% of food or showers or care because I sure wasn't giving it my all. I left that house and managed to graduate from high school with honors, 11th out of 500 students despite my senior year being mostly self-taught because I moved and hadn't been taught the basics of the material. In college so far I've kept entirely above 90s. My point is, 80% means nothing. You might not get into Yale or Harvard for it but if your hopes are just to graduate (maybe even valedictorian depending on your school) and get into college, you've got a really good chance. Keep up the good work!

Geography hardly changes and Math never does. Why is this shit so hard for people?

A 90 and and 87 are both Bs. In a lot of places a 93 is the lowest A

Tell him that them. Call him on his shit.

That's some thick irony. You'd think if he was your own teacher, he would at least know where you seem to struggle and point it out to you.

If he got a problem, tell him "**** around & round it up."

Wow, what an ass!!