Pete Wentz -- Look Ashlee, No Ring!

2/18/2011 1:00 PM PST
Pete Wentz flew to Japan for some event on Friday ... but left his wedding ring at home.

Earlier this week, the 31-year-old reunited with his estranged wife Ashlee Simpson for a little Valentine's Day lunch.

But Friday, Pete didn't put a ring on it,  so it looks like he's single, ladies.