For those of you who read the comic and did not get it, allow me to explain:
1. Herg offers SPN a tortilla chip. SPN accepts Herg's offer.
2. Herg turns around, takes out a cup (or whatever the hell it is) of super chili hot sauce, and dips the chip in the hot sauce.
3. Herg gives the chip to SPN.
4. SPN eats it.
5. SPN spots the cup of hot sauce, which he mistakes as a beverage.
6. SPN takes the cup, drinks the hot sauce, thanks Herg, then leaves.
7. AAAAAAAAAAAAAAAaaaaaaaaaaaaaaaaaa.
Not funny.