Glowstick
"Dick no," Bruce says as he tries to slowly push the door close. He doesn't want to smash the door on Dick's fingers. He just wants to dissuade the younger man from entering with that thing he's holding.
"C'mon Bruce," Dick struggles against the door, "the psychiatrist said experimenting is good."
Bruce sees the younger man tighten his right hand against the doorframe and feels the push from the other side.
"The answer is still no," Bruce glances at the clock on his bedside table and rubs his face against the door, "look, it's three o'clock in the morning. I need to be at the office at six. Can this wait till later?" He hopes the tone of his voice conveys the tiredness that he's fighting to keep.
"No, I mean yes, but no, Bruce," Dick not-whines, "it'll only take a couple of seconds. Well maybe not seconds but come on."
"No," Bruce sighs
"But I've prepared. I mean, I'm using one!" Dick hisses and Bruce sees his hand retreat, thinks finally until he hears clothes rustling followed by muffled groan.
And Bruce knows no one walks these halls at three in the morning. Tim won't be visiting for another week and Alfred's settled down for the night. But he knows Damian is awake, and is too stubborn to try the warm milk method that Alfred had used on Dick, Tim… Jason.
And a few moments after another groan Bruce hears a telltale creak coming from across the hall. Bruce feels adrenalin start surging, overpowering the fatigue and he silently curses Dick as he opens the door and yanks the younger man inside.
Has a thought too late, watching Dick do a victory dance with thingbobbing in tune, that perhaps Alfred had left a door ajar and a draft had pried it open. Or that the door opening was too well timed to even be random.
"So," Dick stalks closer, "did I mention I also took some Viagra."