Steve has to give the guy credit, even if it's some alternate version of himself: he's not sure he'd handle having a wolf jumping at him as well. Actually, maybe he would since this is some him.

God this is confusing.

Still, the sniffing and even having the cap in his teeth tell him this guy is not any kind of wolf and gives him a faint, barely there hint of Sam.

He stays just out of Steve's reach with the cap, not so much teasing now - though there is totally some of that - as trying to... lure him.