make a mountain out of molehill
A:I'm so bored all day.
A:我烦死了。B:Why?
B:怎么了?
A:Jack borrowed a large sum of money from me and didn't pay me back.
A:杰克借了我的钱，而且也没还。B:Don't make a mountain out of molehill. I'm sure he'll do that on his payday.
B:别小题大做了，我相信发了薪水他就会还给你的。