lips on garden shears (слэш)

Harry is in shock and disbelief when he coughs up flowers after an Occlumency lesson.
Through Legilimency, Snape discovers that Harry has hanahaki over him... and while it shakes him, and he would never admit, even moves him as he feels the depth and complex yearning he feels in Harry's mind…
...he is still nonetheless tasked with killing Albus.
Snape is relieved that it should kill all of Harry's romantic feelings for him, and Harry would be able to live. For he knows he won't survive.
(this is a threadfic)