At the moment, he's big news across the pond because of some sneaky holiday snaps but he has been so since he turned on the full array of his talent for Aston Villa in the FA Cup-semi-final and English fans realised that the FAI already had hooks in.
Two things spring to mind immediately about the pictures. What an idiot and it must have been some party.
He's an idiot because he opened himself up to the type of comments on websites like the one which said "He's declared for Ireland then", a sly, racist dig, but it must be said, a funny one.
He's not an idiot because he did what most lads his age will do at some point during the summer and allow a mixture of sun, sea and sangria to overwhelm them. It's not a mortal sin.
But Grealish clearly has to make choices about his life other than which country he plays his football with. He could have a look at the company he keeps for a start and realise that there is a price to pay for the fact that he will never have to work a conventional day in his life.
It's not the first candid snap which has left him with a publicity firestorm to deal with and it won't be the last if he doesn't wise up. He shouldn't live like a monk but he can afford some privacy.
Last Saturday's draw with Scotland at least clarified the big decision he has to make in the next few months. If he is doing a calculation, it should now include England's certain presence at the finals in France and Ireland's likely absence.
It should include the fact that Martin O'Neill desperately needs another option in terms of goal scoring and that Grealish would almost certainly be thrown straight into the action for Ireland in the final four games of this qualifying series. Desperate measures and all that.
Against that is the fact that Roy Hodgson has done the heavy lifting now and can afford to try bright young things in his team in England's remaining fixtures. But he could throw Grealish in for a run and still lose no sleep if he didn't think him worthy.
So choosing England is still a gamble for Grealish if he is making a calculation in his head. It would have helped if Ireland had beaten Scotland and at least kept the contest even.
Russia 2018 is a long time in the future for a lad of Grealish's age and anyone looking at Ireland's current circumstances would not be confident about qualification even before the draw takes place in St Petersburg next month.