That Spike still hesitates speaks volumes, and makes him even more determined to offer what he's offering. It also, the longer he waits, makes it harder to keep his arm held out like that, in case Spike sneers at him. He shrugs, coming a step closer, so his arm's practically under Spike's nose.
"You might as well have it. It's only going to go to waste otherwise."
Besides, they really need to talk, and he senses that's not going to be possible until Spike's bloodlust has died down.