I had been so nervous that I had dropped some of his lunch down his lap and was now trying in vain to mop it up, so that a good patch of his trousers was sopping wet.

我太紧张了，把他的一些午餐掉在了他的腿上，现在想把它擦干净，但徒劳无功，以至于他裤子的一大块湿透了。