Crackish idea that came from a Mean Girls of Panem post. Yes, I know that drinking water won't actually cure/prevent a hangover, but supposedly it helps, and I'm too tired to come up with another way to have Katniss talk to drunken Haymitch.
Katniss set a glass of water on the table in front of Haymitch, letting it land with a thud. "Drink it," she ordered.
Haymitch laughed, a dry chuckle. "You think you know what's best for me?" he drawled sarcastically.
"I know that you've had too much liquor," Katniss replied. "And it'll be worse for you in the morning if you have an empty stomach."
Haymitch rolled his eyes and gulped half the glass. "Happy?"
"Better."
He chuckled again. "Sometimes I don't know why sweet little Peeta's so crazy for a harsh girl like you."
"He's not crazy for me," Katniss countered. "He likes me, but —" Haymitch stopped her reply with an upheld hand.
"I found his diaries the other day — journals, whatever he calls them. He drew hearts all over them. 'K & P,' 'Peeta loves Katniss,' things like that. One of them even said 'Mr. Katniss Everdeen.' Real cute, actually."
Katniss was taken aback. "You're only telling me this because you're drunk," she said.
Haymitch snorted with laughter. "There're a lot of things I wouldn't tell you sober. For instance, you know what Effie and I did the other night when you two left us alone?"
Now Katniss held up her hand to stop his speech. "I don't want to hear it," she said wearily. "Finish that water." Haymitch gave a wide, fake smile as he raised his glass in a parody of the "cheers" sign, letting her know that he was only humoring her. She would have been more frustrated by his determined drunkenness if she hadn't become accustomed to it.
Instead, she became distracted by other thoughts. In her crazier moments, she had, in fact, wondered what it would be like to be identified as Mrs. Katniss Mellark, or even Mrs. Peeta Mellark, under the antiquated naming system people of Greasy Sae's generation used. But it seemed that Peeta was a full step ahead of her. A year ago, she thought, she would have been upset by it, but now she was inclined to agree with Haymitch: it was a little unsettling, but it was cute.
"Mr. Peeta Everdeen," or even "Mr. Katniss Everdeen." Yes, it did have a nice ring to it.
For the reviewer who asked, the idea of Peeta taking Katniss' name instead of the other way around is the joke of the story, and derived from the aforementioned Mean Girls of Panem post. Plus, I've always thought it was odd and sexist to expect a woman to change her name when she married, but not a man.