Patrick Mahomes' brother, famous TikTokker Jackson Mahomes, was so tired of being heckled by Ravens fans Sunday ... he straight up doused the men with water.
The scene went down just minutes after Patrick's Chiefs lost a heartbreaker in Baltimore, 36-35 ... when Ravens fans appeared to be talking smack to Jackson.
In footage of the incident, you can hear people telling the younger Mahomes, "I'm so sorry for you! I'm so sorry for you!"
Another fan added, "Go home, Jackson!