"I pke a star" 可以用 "I have a crush on a celebrity" 来表达。
"Crush" 是英语中的常用词，它的意思是喜欢，迷恋，特别喜爱的人。它最早的意思是碎片，后来引申为指对某人的迷恋。
例句：
I have a crush on Ryan Reynolds. (我迷恋瑞安·雷诺兹)
She's been nursing a crush on him for years. (她对他有暗恋已久)
I had a crush on her in high school. (我在高中时对她有迷恋)