On July 23rd, 2014, the following exchange took place in HipChat, terminating in what could be considered to be a "joke":

[10:20 AM] Lauren: @ali are we having dos toros, too?

[10:20 AM] Alexandra: @lauren yup!

[10:21 AM] Lauren: (thumbsup) (thumbsup) (thumbsup) (thumbsup)

...

[10:25 AM] Stephen: That's BULL!!!!!

To "get" this joke, you need to know two things:

1. The fact that "dos toros" means "two bulls" in Spanish. This is widely-held knowledge that can be expected of most people living in a major metropolitan area, whether or not they are fluent Spanish speakers.

2. Why this particular form of joke should be funny. This is a lot more complicated. In this case, the reason some might find comedy here is due to the two meanings of the word "bull". Stephen meant that it was "bullshit" that we were having tacos again, but was also referencing the name of a taco place. The joke invokes the cognitive process of disambiguation, which Yus (2008) explains as follows: "When the utterance contains a polysemous or potentially ambiguous word, one of its senses has to be selected according to contextual constraints".

There was some debate as to whether or not this was actually much of a good joke at all. I think it was, and hope you found this explanation enlightening.