It starts as a joke. As a bet. As a challenge.
Can Jason find something Tim hasn't trained in? He's a perfectionist and a control freak; when he isn't patroling, he's working on his cases, and when he isn't doing that, he's practicing drills.
So that's all it is, really. A stupid bet. The stakes aren't even that high: loser has to buy dinner.
But Jason grins like someone just promised him the world, and he asks whether Tim's ever trained in the Ivy Protocol.
Tim, who has memorized every contingency in the Batcomputer and made up forty-seven new ones besides, has never heard of the Ivy Protocol.
The Ivy Protocol, Jason tells him, is for when you get dosed with pollen and can't retreat. Can you keep fighting? Can you keep your cool, in the face of whatever distraction comes your way?
Tim stares. Jason stares back.
Tim is almost certain that Jason is making this up on the spot, but he's also certain he likes the slant of Jason's smile and the hungry light in his eyes. His mouth is suddenly dry, and he's suddenly sure that he'll be very distracted indeed, but he admits that he has not, in fact, trained for the Ivy Protocol.
Jason's smirk grows a little more pleased when he offers to help.
So that's why Tim has been dosed with a sample of Ivy's newest strain.
That's why Tim is sitting in his safehouse, staring at the computer as his brain slowly bluescreens, hyper aware of Jason leaning up behind him, making idle suggestive commentary in his ear.
That's why Tim is running maintenance on his grapple lines and inventorying his equipment while Jason trails teasing fingers up and down his thigh.
That's why Tim is going five rounds with Jason on the mats, and when Jason pins him the final time, he can't help but grind up into the hold, pressing his clothed erection up against the meat of Jason's thigh.
When Jason presses his hips back down to hold him still, Tim tries in vain to chase after the pressure.
Jason only laughs, voice low and teasing, and tells him he plainly needs more practice. He's getting more distracted by the minute.