Who knew that John Mayer was partying pals with deejay (and Lindsay Lohan’s ex) Samantha Ronson and her fashion designer sister Charlotte?

At last night’s one-year anniversary party for Juliet Supper Club in New York City, “he came with Sam and Charlotte, and some other friends to watch Sam spin. They all came and left together,” says a source of the group, which downed Svedka vodka. “They asked for a table with a direct view of Sam so they could watch her deejay.”
Adds the source, “They chatted, drank and had a good time. Nothing too crazy happened.”
While Mayer’s making the New York City nightlife rounds, he was a no-show at a birthday party this week for Kim Kardashian, whom he was linked to recently.
Meanwhile, Spencer Pratt’s sister Stephanie was also nearby at another table, partying with a group of girlfriends.