"butthurt" is the pain you feel in your anus after being anally raped.
If you scroll down on that knowyourmeme page that you linked, you will see a set of memes in the "Buttfrustrated" category. The Brony meme has a set of insults that reference the anal rape: "Im sur thers sumpony who can help fill ur ass with semen laced hrut".
The percentage of cases in which a person is referencing "butthurt" to indicate a spanking is vanishingly small. Play the game "League of Legends" and complain when you lose. Ask people what they mean when they claim you must be "butthurt".
If you scroll down on that knowyourmeme page that you linked, you will see a set of memes in the "Buttfrustrated" category. The Brony meme has a set of insults that reference the anal rape: "Im sur thers sumpony who can help fill ur ass with semen laced hrut".
The percentage of cases in which a person is referencing "butthurt" to indicate a spanking is vanishingly small. Play the game "League of Legends" and complain when you lose. Ask people what they mean when they claim you must be "butthurt".
Did I just type those words?