John Mayer and Katy Perry got into a lovers’ spat at an MTV VMA after-party. Sources tell us that Mayer, who didn’t accompany Perry to the event Thursday, hoped to spend quality time with her afterward. But the “Part of Me” singer wanted to party with friends. The two walked into the House of Hype Power Players event at the Beverly Hills Hotel with about 10 people, but we’re told: “John was in a grumpy mood and wanted nothing to do with the party or the group — he just wanted to hang with Katy. Immediately, when they sat down, he had his hand on her back and kept pushing for them to leave.” After the two had a tense conversation at the table, Mayer finally had enough and took Perry to the Polo Lounge at the hotel. They sat in a back table on the outdoor patio for a while before heading out by themselves. A source told us: “Katy’s friends texted her throughout the night to come back and hang out, but she stayed with John although she wanted to come to the party and celebrate with everyone.”