他们总是拿我开玩笑来取乐。

They always make jokes ___at ___my ___expense for entertainment.

因为他超重，同事们经常开他的玩笑。

Because he was overweight, his colleagues often made jokes ___at ___his ___expense.

在会议上，他开了新员工的玩笑，让大家都笑了。

During the meeting, he made a joke ___at the new employee's ___expense, making everyone laugh.