Bucky still might have problems remembering Steve's not as fragile as he used to be, but the grips Steve sometimes get are reminder enough when Bucky does forget. He grins a little at Steve's reaction and he can't help but take a little pride in knowing he does this to Steve, he can unravel his best friend with the lightest of touch and a well-placed kiss, it was a very heady feeling.

"Now you're just tryin' to show off, Rogers." To illustrate what he meant, Bucky's fingers curled around Steve's length as he ran his tongue slowly up the side of it. It wasn't massive but it was impressive and definitely bigger than Steve's old 'equipment.' That serum really had made the good better.

Bucky was mostly teasing and he showed it in the way his hand and mouth never left Steve's sensitive skin. He held the base, stroking with his fingers while he licked every side of the length before taking as much of it into his mouth, comfortably, as he could. And then he sucked on it hard.