Kevin Federline is "worried" about Britney Spears and feels that the psychiatric hospital is the best place for her right now, a source tells PEOPLE.
Federline "doesn't want her to get out until she's made progress," the source close to Federline says. "This is obviously going to help her in the end – later, much later."
The source adds: "He's worried. ... He doesn't even know what's going to happen next."
Federline, 29, was not directly involved in the latest events, "but he was aware of what was happening," says another source, a friend of Federline's.
Unlike the first time Spears was sent to the hospital, the children were with Federline, the friend says.
"Kevin legitimately wants Britney to get better. He wants her to be in their sons' lives. He wants them to have a loving relationship. He wants her to get healthy so she can be the mother they need and deserve," says the friend.
This is the second trip to a hospital this month for Spears. On Jan. 4, she was forced into the hospital following a tense custody standoff involving sons Preston, 2, and Jayden, 1. A court commissioner has since stripped Spears of visitation privileges.
A third source close to Federline says that getting medical help again for Spears, 26, "has been planned for a long time. Her family is behind this."