Julian Edelman wore a T-shirt with a picture of New England Patriots teammate Rob Gronkowski on it, and then Gronkowski wore a T-shirt with a picture of Edelman wearing the T-shirt with a picture of himself on it (you following?), so of course this just happened:
Strap yourselves in. This could theoretically go on forever. At the very least, the two players have months to kill before training camp starts.
Feature photo courtesy of Mark L. Baer-US PRESSWIRE / Reuters