John Cena warns Nikki Bella about his nude scenes.

The 40-year-old star - who has made the transition from wrestling to acting over recent years - has revealed he runs his nude scenes by Nikki after she was less than impressed when he stripped down in 'Trainwreck'.

John - who also appears nude in new movie 'Blockers' - told 'The Ellen Degeneres Show': ''For the 'Trainwreck' one, I did not. I was just like, 'it'll be fine'. I was wrong. So that was a problem, and that ended up being a tough discussion.

''Now we review all of the material that is thrown in my direction and we come to the conclusion that it will be OK.''

John's confession comes shortly after he revealed he is ''on standby'' for his wedding to Nikki.

The loved-up duo previously postponed their wedding plans, and John admitted he doesn't know when the big day will eventually arrive.

He explained: ''I was able to let Nicole plan the bachelorette party and she just finished that. And now I'm just kind of on standby to know when it is and where it is, and I'll be there.''

John also revealed that he'll be preparing for his wedding day by learning to dance.

He shared: ''I am super excited and I'm going to have to learn a dance.

''I promised Nicole that I would spend the last half of April learning a dance. It's not going to be any good, but I'm going to do the best I can ... I'm going to put the time in because I want that moment to be special for her.''

John - whose first marriage to Elizabeth Huberdeau lasted from 2009 until 2012 - has been dating Nikki since 2012 and the high-profile couple became engaged in April last year.