They kind of gloss over it, but when he was sent down to Utica and then wasn't picked up by any team at the trade deadline he felt "rejected" and took it out on MP. Like, verbally. MP says he said some "hurtful" things to her,and that he blamed her, but she doesn't elaborate.

She reveals this in one of the interview things that they show, while their at his house in London discussing the wedding/his training/next season and she's also like "OMG He's finally talking to me about how he's feeling!!!" and you're just kind of left sitting there like "He should of done that before he blamed you for shit that is not your fault??? This isn't healthy at all!!"