What a bad temper my uncle has. but my cock squirts while he fucks my ass.

I've been working at my uncle's house all summer helping him with the company paperwork and today is my last day before starting university. he has always been very dry and grumpy with me and today i want to know why. when i ask him, he tells me to take off my pants and come closer that i will understand. suddenly he starts rubbing my cock and he lies me on his back on his table to fuck my ass. what an explanation.