AceShowbiz -

Charlize Theron held a birthday party on Sunday, February 17 for her son, Jackson, who turned one. Some celebrities such as Sandra Bullock and Chelsea Handler were invited to the party. Sandra arrived at the party with her son, 3-year-old Louis. Chelsea's Limousin, meanwhile, arrived at the same time.

Sandra and Louis approached Chelsea and the three of them walked to Charlize's house together. A witness told E! News, "Sandra Bullock was one of the first guests to arrive with her son Louis. As they walked into the party, they bumped into Chelsea Handler who had also just arrived in a limousine. They all walked in together and headed for the backyard where children's music was playing and kids were running around."

A source added that it was a "a low-key party with only close friends and family...There was a lot of laughter and screams as everyone had a good time." There were around 20 people invited. The parents enjoyed the time talking to each other while the kids playing around. Us Weekly's source described, "The kids were running around the yard while the adults sat and chatted. Jackson was practicing walking the whole time and was very happy and active."

The same source stated, "At the end of the party there was a birthday cake and everyone sang to Jackson." The source said that Louis and Jackson quickly became friends as saying, "Louis and Jackson had a great time running around playing together, but they were both worn out and looked ready for a nap." Bullock and her son stayed for two hours.