pull on one's ear 是什么意思？

My twenty-first birthday is on Saturday,ang I'm going to go out with some friends.To wish me a happy birthday,they're going to pull on my ear 21 times,once for each year.It's an old custom.Some people pull on the ear just once,but my friends are very traditional!
这星期六我将迎来自己21岁的生日,我打算和我朋友一起出去庆生.为了祝愿自己生日快乐,他们准备在我的耳朵上拉21次,每拉一次代表一年.这是一个旧的传统.一些人仅仅只拉了我一次耳朵,但是我的朋友还都是相当传统的!

仔细听