Truth be told, Spike would've been disappointed if Jack just laid down and took it. The struggle is half the fun and the thrill goes right down to his bones when Jack's fist connects solidly with his jaw. He gets knocked back, loses his balance enough to tumble back on his ass with a heady giggle.
"That's more like it!"
He starts to push himself back on his feet but it's slower work than he'd like. Now would be a good time to take the upper hand.