Ahri proposed Ezreal to have a classic magic duel outside to train their abilities. He accepted but had no idea what was her real intention with this duel. She didn't want to train at all, she wanted to toy with him using her recently acquired ability to shrink things. She still proposed a duel instead of just sneaking on him and cast that spell because she wanted to prove to herself that she could use it in battle.
The duel starts as normal with both of them exchanging magic blows at themselves. After this nice warm-up, Ahri casts her shrinking spell and lands a direct hit on Ezreal, who wasn't suspecting a thing, turning him into the size of a pebble. Also, to prove to herself that she is talented with this spell, she only focused it on his body and his underwear while leaving the rest of his clothes untouched, to also humiliates him a bit. And she did pull it off, he's now very small with only his underwear on, which makes him feel scared,confused and also embarrassed. She's happy with herself for managing to pull this out, and she's also happy that now she can have the fun she wants to have.
She takes off her shoes and makes sure to have a lot of dirt on her socks, then she approaches him. Her footsteps feel more and more like small earthquake to him as she gets closer. While still confused at what's going on, he can feel that she has a devious intention by seeing how she looks at him, and he's right. Without warning, she presses her foot on him. He's so tiny that the sweaty fabric makes him stick like lint to the sole of her, and he absolutely hates it. Her sock is really filthy with all the dirt and smells incredibly bad. As soon as he is stuck here, he only wants to get out of there. But slowly his mind starts to change. He isn't focused on the dirt and the smell anymore and is instead focused on how soft her sole actually is, then how cozy and how warm it is. What he never realized is that Ahri has also cast her charming spell on him, slowly hypnotizing him into getting charmed by her foot, and she loves it. She teases him saying that he now prefers her foot over Lux, his love interest, even if it's really smelly and dirty.
After Ezreal has completely succumbed to her charm, she toys with him further by pressing down her foot his small body. She also teases him even more, telling him to worship her as his new goddess, enjoying this feeling of absolute domination. She can even feel him getting turned on by this, which she thinks is hilarious. That is of course the result of her charming spell, that seems to work even more on him since he's tiny, because nobody on their right mind would enjoy being under this nasty dirty sock and suffocating under this tremendously awful smell.
All characters are 18+