I suppose this Beetle Bailey comic is a repeat of the second-oldest joke in the book, descending as it does from sixth grade English (Hi, Mrs. Clemens!). Lots of folks get confused when they have two objects of a single preposition, and the mistake is so common that it’s worth repeating the joke as a reminder. The trick, by the way, is to think the phrase without mentioning the other guy; then it’s easy to get the correct word.
The other second-oldest joke, I suppose, is the one about the restaurant manager who goes someplace else to eat.
What? You want to know the world’s oldest joke? Well, just between you and (ahem) me, it’s somewhat scatological, so I won’t repeat it here, but they found it on a cuneiform tablet that dates to about 4000 years ago. Google “oldest joke.” Reuters has a short article about it.