Some people think that's the case, after the singer was spotted getting close with Allison Williams, the actress who plays Marnie on HBO's hit series GIRLS.
Just a few days ago, John was spotted with his girlfriend Katy at the Presidential Inauguration, so what could have happened?
According to witnesses:
Allison stunned attendees at an event at Manhattan’s Jane Hotel on Friday night when she walked in with the musician.
The two attended an intimate event for the fashion store American Two Shot where an onlooker told the British tabloid that, “John had his arm around Allison’s waist. They talked for a bit before leaving.”
While things might have looked suspect, chances are it was a casual encounter. John is best friends with Allison's alleged boyfriend Ricky Van Veen, so this could be very innocent.
However, knowing John Mayer's Casanova ways, he doesn't come out looking the best in this situation!
Do you think John Mayer and Allison Williams are messing around?
SOURCE: NY Daily News