Well Spike himself has admitted in his past he has bragged, and remember his comment to Angel during their fight in Destiny. Yes I know that was in extreme circumstances, but I could see Spike bragging with the right audience and under the right circumstances.

"And to repeat, I'm not forgiving if the reason for these problems is because IDW wants to pander to a bunch of boys."

Joss is IMO is guilty of doing exactly the same when it comes to season 8 of course.