It wasn't serious—it was all done in fun.

那不是认真的，全是闹着玩的。

《牛津词典》

Speaking of fun, what have you done for fun while you've been here in Orlando?

谈到乐趣，你有什么做的乐趣，您在奥兰多期间有什么事情值得一乐呢？

youdao

In fact, those thousands of hours of forced work at math, done for a grade and not for fun or for any practical use, are what make math seem so difficult and intimidating.

事实上，那些在数学上的强迫的数千小时的学习，为的是成绩而不是乐趣，没有任何实际用途，正是这一点，使数学显得如此艰难和恐怖。

youdao

Having burnt out pretty badly on first-person-shooters, the fun and occasionally grotesque game has done a good job at keeping my fleeting attention in check.

FORBES: Connect

"I've done a few outrageous places in the city for divorced fathers and bachelors, and it's a fun thing to do because it's like a second childhood, " he says.

WSJ: Looking Out for No. 1 - WSJ Mansion