Hidden Things

Yes.

Once in a while, mutual perversion with one's lover is fine, too.

Love that now they embrace their perversion and are all the closer for it!

Ok is this something Japanese I'm too European too understand? Why would you hump a schooldesk?

Ok, so this was before school started. I can understand her getting there early enough to "get the job done" and plan for cleanup time, but full naked fucking takes quite a bit more. I didn't notice them locking the door so was he hoping to get interrupted and awaken to another kink?

Why is there a sudden couch in the classroom

Just as long as they don't get caught by someone else. That either leads to NTR or
cuckoldy.