This is definitely more like a joke than oneshot. Enjoy

Ash and his team arrived at a hotel, where they will stay overnight
Serena: We're here, everyone

Clemont: Good, 'cause I need somewhere to pee

Bonnie: Oh big bro. You should let it go, I know you can't hold it back anymore

Clemont: You're right, Bonnie. Gotta go fast *ran to the bathroom with Sanic speed*

Serena: So Ash, what you gonna do today?

Ash: You know, today I don't feel like to do anything

Bonnie: Ash, you should train your Pokemon. You should work

Serena: She's right. But I think you should take a day off

Ash: Thanks Serena. Oh, and Bonnie, can you leave the room, we need some privacy

Bonnie: Ok, and Serena *whispered to Serena* That's your chance, just do it

Serena: *blushing*

Ash: So Serena, about what happened in the forest, well, is it too late now to say sorry?

Serena: No

Ash: Wow, that's short

Serena: I know. Anyway, I just think about my next Pokemon Showcase

Ash: What, worried?

Serena: Yeah. Lately I've been losing sleep because of that

Ash: Oh that's bad. Don't beat yourself up. Sometimes you come last but you did your best

Serena: Thanks, Ash, that's really help

Ash: You're welcome. After all, I was there for you in your darkest time

Serena: Wow, this starts to become nonsense but I like it *thinking* There it is, Serena, time to confess *spoke out* Ash, there's something I want to say

Ash: Yes?

Serena: Well, I got this feeling inside my bones. It goes electric, wavey when I turn it on

Ash: And what is that?

Serena: T-That's love, Ash. I love you. But I think you don't like my appearance, huh?

Ash: No, Serena. I love you just the way you are

Serena: So that's mean...

Ash: Yes, I won't hesitate no more. I love you, Serena

Serena: Oh Ash *kissed Ash passionately*

*After a while, Ash walked out and saw Clemont*
Clemont: What took you so long, and why Serena inside our room?

Ash: I've just had sex- Oh shoot, wrong song

Clemont: What do you mean?...