A billboard advertising Texas fast-food chain Whataburger in San Marcos has a location too convenient to be a coincidence--right next to the city's In-N-Out location.

Twitter user @BuddyXXVII posted an image of the billboard behind In-N-Out's sign last August along with a message saying, "funny how there's a Whataburger billboard right behind In-N-Out."

Since then, other Twitter users have weighed in on Whataburger's "trolling."

The rivalry between the two fast-food chains frequently makes headlines. In June, a report by market research company 1010data found that Whataburger sells more food and has a more loyal fanbase than In-N-Out.

In October, a Business Insider study concluded that In-N-Out was the most popular fast food chain in the Lone Star State.

In-N-Out has been encroaching into Texas since 2011. The San Marcos location opened its doors last June.