I'd guess he thought that the international stardom that his fabulousness deserves had finally arrived, and he needed to dump his familiar boring British wife and get himself a racier, sleeker, more glamourous partner to match his glittering career. What was fitting for a career as a celebrity cook in Britain: stable marriage, hard grafter, good dad, family man, etc, just wouldn't cut if for a megastar cook/ celeb in the US.
Now the series has been cancelled, and the new relationship has petered out, he is back here, and oh yeah, the adulterous mid-life crisis fanny rat persona just doesn't cut it for the career as a celebrity cook in Britain . . . which is all he has got left.
He is thus trying desperately to get back into the boat named "Good Husband and Father" because he needs it to get back to the safe port of British Celebrity (twinned with National Treasure) but unfortunately the ship may have sailed.
He may be marooned forever on the Island of Elvis [fat years] Lookalikes.