Warning: The following contains spoilers for Avengers: Mech Strike #4, by Jed MacKay, Carlos Magno, Guru e-FX and VC's Cory Petit, on sale now.
As an on-again off-again member of the Avengers, Spider-Man has grown close to several of Earth's Mightiest Heroes including Wolverine and Jessica Jones, who have made their way into Peter Parker's world quite frequently. Recently, however, Spider-Man had an experience highlighting his strange relationship with another Avenger: Black Widow.
Spider-Man and Black Widow's latest interaction takes place in Avengers: Mech Strike #4. In this issue, the Avengers are going over their plan to defeat Kang, the Conqueror. Spider-Man, in particular, isn't sure if their plan is going to work. To ease the wall-crawler's mind, Black Widow gives Spider-Man a metaphor about killing an enemy. Natasha says that the knife which they show their opponent is not the same one that they'll use to kill them. In fact, it will be the small, quiet knife that presents the real danger.
While this metaphor is useful, it also makes Spider-Man very uncomfortable. The idea is meant to help Spider-Man understand, but Black Widow comes across in a very threatening manner, to say the least. During her speech, Black Widow slowly approaches the web-slinger with one knife, before sneaking up on him with another.
By the end of the analogy, Natasha has two knives pointed to Spider-Man's throat, that understandably make him uncomfortable. The body language in this scene makes Black Widow come off as very predatory, as if she's caught Spider-Man in her proverbial web. By the time Captain America breaks things up, Spider-Man wipes his forehead in relief.
Since Spider-Man and Black Widow are both spider-themed heroes, their respective roles in this scene make sense. Even Black Widow's namesake is predatory, known for devouring its mates and eating other arachnids. Spider-Man, in this case, is the male spider or other arachnid, ensnared in Natasha's web.
Considering the fact that Black Widow is a trained killer, while Spider-Man is a more clean-cut, traditional hero, it makes sense that Peter would feel threatened by Natasha. At the end of the scene, Black Widow tells Spider-Man to stick with her and they would have fun. Spider-Man can only respond by noting that this is the most threatening thing Natasha has said yet. Clearly, Black Widow's tactics strike real terror into the web-slinger.
While this is an interesting scene, it does take place outside of the main Earth-616 Marvel Universe. In the mainstream universe, Spider-Man's relationship with Black Widow is similar, but not quite the same. For one thing, the two heroes don't have much of a relationship outside of the occasional team-up or their shared time with the Avengers.
When they do interact, Spider-Man and Black Widow have a tendency to work well together. Even so, it took time for the two heroes to reach that point. They initially crossed paths in 1970's Amazing Spider-Man #70, by Stan Lee, John Romita Sr. and Jim Mooney. At the time, Black Widow was hunting Spider-Man, trying to obtain the secret of his powers.
In their first meeting, Natasha was the predator and Peter the prey, just like in Avengers: Mech Strike. Yet Black Widow underestimated her perceived prey, who proved to be a match for her. This is different from Avengers: Mech Strike, since Spider-Man of Earth-616 showed Black Widow right away how dangerous he can be. Over the following years, the two have worked well together, especially in 2012's Amazing Spider-Man #684-687, by Dan Slott, Humberto Ramos and Stefano Caselli.
Spider-Man and Black Widow have come to respect each other and work together on several occasions. This is fairly different from their interactions in Avengers: Mech Strike, where Black Widow is portrayed as a much more threatening presence to her unsuspecting teammate.