"Jesse seemed very tense and kept biting his lower lip," an eyewitness says. "Still, he seemed to want to keep the morning as normal as possible for the children's sake and walk them into school hand-in-hand."
James, who was wearing his wedding ring and a black hat pulled down low, was driving quickly and appeared somber, according to onlookers. He was seen earlier in the morning at the family home he has shared with Bullock.
PHOTOS: Sandra & Jesse: Scenes from a Marriage
Bullock, 45, left the house on Monday just days before the reported infidelity surfaced, a source tells PEOPLE.