Kazuha was your friend, and you liked him and clearly you were very forward about it by flirting a lot

You decided to meet up with friends: Kazuha, your girl best friend, Lumine and her brother Aether

you were sitting at the table and gossiping, then suddenly you had an idea to tease Kazuha, sliding your leg up Kazuhas pants in a flirty manner

Kazuha: he choked on his water

You: "Are you alright~?"

Kazuha: he glared at you embarrassed as the siblings didn't seem to notice