When you are the child of an international celebrity, choosing a birthday gift can be daunting. Or, it could be a simple message that leaves you in splits. So when J.K. Rowling celebrated her 51st birthday this Sunday, she made a funny tweet about her son's gift to her being 'unacceptable'. What followed was a game of retweets where fans told her it was the teenage lingo for, "I love you" to many hoping their kids would do the same for them. Here's what happened on Rowling's Twitter account on her birthday.

Her fans had some really interesting things to say.

And there were those who took notes.

And her son seems to have amassed quite an appreciation for his humour.

Rowling's gift seems to have made her son a favourite with her fans too. Many even ordered the same mug the moment she posted it on Twitter. The writer just released, 'The Cursed Child' which she says brings the Potter story to an end. After the response to the mug, the new book does not seem to be the only bestselling item on the site.

We sure hope you had an amazing birthday, Ms Rowling. Your writing made the world such a better place for so many!