Find out why after the jump. Apparently Russell planned on flying all of Katy’s family to the UK to spend Christmas with his parents in London. Then the couple would jet off to India for a 2nd honeymoon. Those plans were scrapped when the couple “had a massive fight,” an insider tells Us Weekly.

“She was like, ‘F–k you. I’m going to do my own thing.’ Russell replied, ‘Fine, f–k you too.’”

So, Katy jetted off to Hawaii and was spotted swimming in the ocean sans wedding ring :o

Neither Russell nor Katy have tweeted anything to hint at problems BUT Russell hasn’t tweeted at all since December 18th. Hmmm.

So, will the couple make it through this? Us Weekly’s source says:

“The split may come soon, but they are both so dramatic and volatile, the relationship could become great again.”