Today, I went to see her parents with my girlfriend and got my father-in-law drunk. She patted me on the shoulder and called me brother. I was a little tall and let go of my father-in-law

Find a chance to go again, and when you meet your father-in-law, just try to be respectful. It's no big deal. I drank too much and chatted hot, which proves that I approve of you. But if you say yes, you will make him feel uncomfortable, so if you go again, try to be respectful and make him feel that you are a nice person. Calling brothers is just drunken talk.