Katy Perry Dresses John Mayer Up As Santa

Could Katy Perry and John Mayer be getting serious?

Katy posted on Twitter a picture of John in a Santa suit and it looks like John doesn't mind dressing up in a silly costume and posing for Katy.

John Mayer as Santa

Some say that he's looking seductively at the camera for Katy. Um, yeah, you decide.

Katy captioned it: "Santa Baby". Yep, the two of them spent Christmas together (this picture is proof!) at her home in California. In face, they spent time with her family too.

Katy is enjoying being with John it seems

"They're happy together and with her family for the holidays," a source told People. "John really likes getting to know Katy's family better. They've spent a lot of time together and really enjoy each other's company. John is entirely focused on Katy."

US Weekly learned from a source (unclear if it's the same one as People): "They are seriously in love and exclusive. John is surprised at just how cool and smart she is. John has proved he's matured and learned from his mistakes... Katy is blown away."

Aw, sounds sweet and we truly hope for Katy's sake John's changed for the better.