Angst
It's like the whole universe stops expanding, the stars stop shining and the world stops spinning and his heart stops beating; everything just stops in that single moment because Toby looks at him with so much regret in his eyes and knows something is wrong just before his eyes roll back and he collapses, leaving Ben all alone.
Smut
Ben nips at the pale skin behind Toby's knees, chuckles when Toby's leg flinches and readjusts on Ben's shoulder to dig the heel of his foot into his shoulder as he smiles up at Ben with glassy eyes and mussed hair, skin shiny and sticky and Ben kisses the pad of Toby's thumb that he runs along his lips before there's a hitch in Toby's breathing and he tenses around Ben.
Hurt/comfort
In the blink of an eye he's pushed to the ground from behind and a heavy boot stamps his face into the wet concrete; the bone in his nose cracks, the capillaries and blood vessels burst and he's choking on his own blood before he can even beg take anything, please don't- and it's the second boot to the face that has Toby gasping awake in Ben's arms.
AU
It's the end of the fucking world and his feet ache from the miles he's trekked, his lungs burn from all the smoke and Toby has to roll his eyes because the only other survivor he's found is a short man with piercing eyes and he's pointing a gun in his face.
Romance
'Toby don't you dare drop me!' Ben warns but his laughter belies any real threat to the words because nothing could spoil this day, even being dropped on his arse - not when he catches the glint of light off his wedding band, so he holds his arms tight around Toby's neck as his new husband carries him over the threshold of their honeymoon suite and drapes himself over Ben on their bed.
Fluff
It starts on Toby's first day at the GP surgery on his way into work he finds it tucked inside the pocket of his jacket, a yellow post-it folded neatly with Ben's slanted scrawl you've got this x; and it continues for months afterwards, and Toby collects each and every one to keep in the creaky drawer of his desk, holding on to all the little pieces of Ben that read like a love letter.
Friendship
What Toby has with Ben is infinitely different from anything Toby has had in the past (regardless of how brief and limited they were) and it's often the most mundane things Ben does for him, like always remembering the avocado for his morning toast, recording Doctor Who and watching it with him so Toby has someone to bounce theories off of that makes that ugly void in his chest ache less and less, because Toby knows he hasn't just got a husband but a best friend.