Makoto x Haruka - Singing, with a reward...

One day, Makoto suddenly wants to sing a duet with Haru! He says that he'll give Haru a reward if he does the request. Little does he know, the reward gets real steamy... ( ͡° ͜ʖ ͡°)

this is honestly a crack fanfiction if you couldn't already tell by how it's written.