Okay, so he's been debating for awhile how to go about this. How to get around to apologizing because, man, he does feel pretty bad about it. He's sort of use to arguing with other Decepticons, but Tailgate? Who the frag fights with Tailgate?

Apparently, Fulcrum does. Ugh, what has he done.

This is primarily due to a difference of when they were forged. Tailgate is ancient and Fulcrum is incredibly young in comparison to a lot of mechs. Describing Primal Vernacular to sound like a petrorabbit being crushed apart by a rusty blender was probably not the best possible thing that Fulcrum could have ever said.

So here he is, after his foot-in-mouth, knocking the door hesitantly to make amends.