[It's not rigid discomfort or an outright no. It's just bafflement. B will take it. He steps in, puts a hand on Xiao Xingchen's shoulder to telegraph what he's doing for someone who can't see it, and pulls him gently into a hug, both arms, putting his chin briefly on the other man's shoulder.

He won't hold him long unless the guy unexpectedly melts into him or something, giving him a light pat on the back before he lets go, but it's definitely a full hug. Maybe it won't do anything for Xiao Xingchen, but it'll make B feel a little better.]