Flowerpot

Everyone can see it

Harry and Fleur are colleagues at a Dragon Reserve.

He thinks she would never lower herself to dating him.

She thinks he would never date a colleague.

Both are oblivious to the other having a huge crush on them.

So oblivious that even the dragons can see it.

You haven't seen subtlety until you've seen a multi-ton scaled winged firebreather playing cupid for a pair of oblivious fools.