John Mayer is still going out of his way to avoid ex-girlfriend Jessica Simpson-even if it means missing an opportunity to support pal Pete Wentz, who is Jessica’s brother-in-law.

We hear Mr. Jennifer Anison, who once accused Jessica of stalking him, showed up at Gallery1988 in L.A. for Pete’s “Without You I’m Just Me” show last week, but ducked out early after hearing the “Sweetest Sin” singer would also be in the house.

“John showed up early for the public viewing and took pictures with fans, but left before the VIP portion of the evening started. He wanted to be there for Pete, but wanted more to avoid the possibility of a dramatic encounter with Jess.”