It's embarrassing, really. The mission was exhausting, sure, but usually Bruce is able to keep himself more or less upright until the debriefing is over. Everyone else manages it somehow. But this time - well, this time he can't help but nod off. He's just so tired, mentally and physically, and Steve's droning on and on about politics and training, and Tony's shoulder is right there...

He isn't sure how long he's out for, but when he wakes up it's just the two of them in the boardroom, his cheek still planted firmly against the other man's shoulder. Jerking slightly in surprise, he mumbles out an incoherent jumble of words to the effect of "W'happen?"