Title text: I was sure he was just getting revenge, but then he did the same thing to Carrie Underwood. Then he mailed me a scone. I think I'm giving up dating.
This comic is a take on one of the typical revenge tactics in dating and in life, which is one person "keying" the car of another. To "key" a car is to drag a key across the side of the car, sometimes multiple times, ruining the paint job. Instead, our friend Beret Guy painted a really detailed key on the side of Ponytail's car in his version of "keying" a car. She broke up with him the day before, as she explains to Cueball, but Beret Guy is so strange that she now can't tell if it was revenge or even if he remembers that she broke up with him.
The title text is a reference to the song "Before He Cheats" by Carrie Underwood; a revenge song in which Carrie Underwood imagines her boyfriend cheating and takes revenge on his prized car. This explains why Beret Guy might also paint a key on Carrie Underwood's car specifically, but it just confuses the situation since it brings into doubt the theory of him "keying" her car out of revenge (there is no known reason or reference to a reason for Beret Guy to want revenge on Carrie Underwood in the XKCD continuity). The second part of the title text in which Beret Guy sent Ponytail a scone further confuses the situation, causing Ponytail to completely give up on dating.
The song "Before He Cheats" by Carrie Underwood; details Carrie Underwood imaging her boyfriend hanging out and flirting with a "bleach-blonde" girl, shooting pool, buying her a drink, dancing, and hoping to "get lucky" with her while she is vandalizing his customized four-wheel drive vehicle by scratching its side with a key, carving her name into its leather seats, smashing the headlights with a Louisville Slugger baseball bat and slashing all four tires in retaliation. She hopes that this will make him "think before he cheats" again.
- [Ponytail and Cueball are walking along.]
- Ponytail: I broke up with him yesterday.
- Cueball: That weird guy with the beret? Did he take it okay?
- Ponytail: He seemed upset. He went out to my car—
- Cueball: Uh oh.
- Ponytail: —and spent the whole night painting a really detailed key on the side.
- Cueball: ...Wait, what?
- [Image of Beret Guy painting a giant key on the side of a car.]
- Ponytail: Then he woke me up to ask what I thought of it. He looked really proud.
- [Beret Guy holding a paintbrush.]
- Cueball: I ... is he playing revenge mind games?
- Ponytail: I genuinely can't tell if he remembers that we broke up.