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 Reuters/Mark L. Baer-US PRESSWIRE