There's really nothing about Allen that annoys Spike except for the way Allen talks about Spike. If he wasn't busting his balls with Buffy and such he'd be chill with him. So, he does find himself wondering when he pissed in Allen's Weetabix. Pff, like you can't make some comments about Adiou dying or keep heavy situations light with mockery. Clearly, the kid is too uptight.
Same back to you, but you know with Allen's thoughts on Spike.