"I'm sorry," he says. He doesn't want to leave it at that but, then, he's not sure if now is the best time to unearth the story behind it because a) Seth doesn't seem overexcited about talking it over and b) he is having trouble focusing on walking currently and thus any advice or comfort he could dispense would likely be in poor supply.

He trips and it takes a little too long for him to right himself, wincing. Yep. Definitely would be in poor supply.