After a fan yelled "f--k you" at Pryor, he responded with the same insult while holding up his middle finger, as seen in this photo courtesy of TMZ Sports:
According to Redskins beat reporter Craig Hoffman, Pryor later took to Instagram (Warning: NSFW language) to explain what led him to react like that, saying he had been called "a N----r" multiple times.
Washington fell to 2-2 as Kansas City prevailed 29-20 in come-from-behind fashion.
The Redskins led for much of the game's first three quarters, and they seized an early advantage on a 44-yard touchdown catch by Pryor just over three minutes into the game.
Chiefs kicker Harrison Butker hit a 43-yard field goal with four seconds remaining to put Kansas City on top 23-20, however, and Chiefs linebacker Justin Houston returned a fumble 13 yards for a touchdown to seal the deal after a failed desperation play.
Pryor finished the game with three receptions for 70 yards and a score, which marked his most productive contest to date as a member of the Redskins.
He leads all Redskins this season with 24 targets and is first among the team's wide receivers with 186 receiving yards.
The 2017 campaign is Pryor's first in Washington, as he signed in free agency after breaking out with 77 grabs for 1,007 yards and four touchdowns with the Cleveland Browns last season.