A man walks in to a bar and says 'OUCH', his friend also walks into the bar after him and says 'ouch'. Seconds later Robstar walks into the same bar and also says 'Ouch. You would think Robstar would have seen the other two morons walk into it.
I have to admit, I must be too stupid to get this. Oh wait - not that. Too smart. Smart enough to know that it's unfunny and nonsensical. That Dennis "chuckled" surprises me not at all.