Lindsay Lohan by Steve Granitz/WireImage.com Lindsay Lohan by Steve Granitz/WireImage.com

Lindsay Lohan has put the kabosh on her mondo birthday party bash, slated for July 4th in Vegas, because though she was slated to check out of rehab later this week, she may extend her stint. "She is staying in Promises for longer than a month," a friend of the actress tells the New York Post's Page Six, explaining, "She is taking rehab very seriously this time, and not messing around." In other words, Promises must keep all the fun and cool cutlery locked up.