Is the California Gurl on her way to becoming a single one as well?
A source confirms to E! News that Katy and Russell have been having "problems" and that they've been spending "a lot of time apart," including Christmas.
Our source adds that things began getting tense between the two in early December and that Katy has been "a mess" about it at times.
Here's hoping the new year will be a better one for the entertaining couple.