Finn is hot, but seems to be flirting with everyone and Poe is INSANELY JEALOUS, but tries to (fails to) keep it to himself. This would be fine for all the others on the base, except Finn being a cocktease and not actually putting OUT is untenable. They force Poe to look into what the fuck, and Finn sheepishly reveals that he just wants to make friends, and the only way he really knows how to do that is to imitate how Poe is friendly with him.

(Basically Poe flirting with Finn without actually saying what he wants from Finn is why the whole base is in an uproar.)