They know

Even the birds are telling them to just do it already.

Look at the one just staring at them.

He knows whats up.

Birds do it, bees do it. Even educated fleas do it.

Not sure if yuri?

I'd just like to draw attention to the fact here that Mitsumoto has managed to give a sparrow a troll face without anthropomorphizing it in the slightest. That's really quite impressive when you think about it.

CHIRP CHIRP MOTHERFUCKERS

They're just giving her a helpful push!