"They had lunch together today with Bronx at the Beverly Hills Hotel," a source told PEOPLE Monday, adding that Simpson is still staying at her parents' home in Encino, Calif.
Another source says the couple are not reconciling, but that their breakup remains friendly and being good parents to 2-year-old Bronx is their priority.
"They just had a meal together with their son," the source tells PEOPLE. "They're both focused on making this transition as easy as possible for him."
The couple – who pals say split because they wed too young, didn't have enough time to spend together and simply grew apart – announced last week that they were going separate ways.
Wentz, 31, and Simpson, 26, wed in 2008.
With reporting by MARISA LAUDADIO