Sandra Bullock takes her son Louis to Matthew McConaughey's son Levi's birthday party in Malibu. Credit: Fame Flynet

Forget Sweet 16 parties -- turning 5 can be pretty cool, too. Just ask Matthew McConaughey's son, Levi, who celebrated his 5th birthday at a star-studded party with A-list guests, including Sandra Bullock's son and NBA player Kevin Garnett's daughters. 

Wearing black flip flops, denim cutoff shorts and a black T-shirt, The Heat actress brought her tot, 3-year-old Louis to the party at the family's Malibu home. The 48-year-old starred alongside McConaughey, 43, in 1995's A Time to Kill and dated for a short time in the '90s. They both also have homes in Austin, Tex., and their kids often have play dates together. 

Garnett, a Boston Celtics NBA player since 2007, also attended the celebration with wife Brandi Padilla and their two daughters.

Levi, who was born July 7, is an older brother to sister Vida, 3, and 7-month-old baby brother, Livingston. Their mom is Brazilian model and television performer Camila Alves, 30, who McConaughey married in 2012.