Kourtney Kardashian met with Scott Disick on Thursday (23.07.15).
The 'Keeping Up with the Kardashians' star came face-to-face with her former boyfriend for the first time since they ended their nine-year relationship earlier this month at the Beverly Hill Hotel in Beverly Hills, where they discussed arrangements for their children, five-year-old Mason, Penelope, three, and seven-month-old Reign.
A source said: "Kourtney met up with Scott to discuss the custody situation.
"She wanted him to know that she was going to go after full custody of their children and that she would allow him visitation rights as long as he is sober during the entire time he spends with the kids.
"For the time being, he is also required to be accompanied by a third party."
The atmosphere between the pair was said to have been "very, very serious" as they held their public meeting.
Another source told RadarOnline.com: "Kourtney and Scott sat outside on the patio of the Polo Lounge.
"She had the cobb salad and Scott didn't eat anything at all. They looked to be deep in conversation and very, very serious."
It was recently claimed Kourtney is seeking advice from lawyer Laura Wasser, who previously worked with her sisters Kim and Khloe on their respective divorces from Kris Humphries and Lamar Odom.
A source told Us Weekly magazine: "[She] is going to seek sole custody of the kids. There's no turning back now, and she is going full steam ahead with figuring out an agreement."