打勾勾 = pinky swear

"My girlfriend and I pinky swore to never fight again."

學起來 :D

可以常常跟女朋友使用 :)

哈哈

many children pinky swear with (his/her)mother if had appointment

"Swear to do something" means that one promises to do something. When you add "pinky" before "swear" it just means two people hook their pinkys to make a promise.