The nanites Natasha accidentally passed to everyone she cares about have been activated in Bobbi, causing her to attack Clint in a berserker rage.
Natasha: I just learned I’ve passed on nanites to everyone I was ever close to, and they passed them on in turn to those close to them. They’re being activated to create a psychotic rage. Please understand, Bobbi—this is for your own good.
Clint: What was that?! Tell me she’s going to be okay.
Natasha: Her pulse is normal. She should wake up soon. I’ve injected myself with counter-nanites supplied by an old friend. The kiss was the quickest way to—well…touching her with my palm would have done it, too. Like this. But why do we wear these costumes if not for the theater.
— From Black Widow: Deadly Origin #3 by Paul Cornell, art by Tom Raney
Thank you Mr. Cornell for this lovely bit of fanservice that shamelessly confesses to being fanservice.
So this is awesome.
Between this and her previous scene with Tony, I really should read this series already. *-*