This is a german saying that is equal to the American "trick or treat", but also may question how the lead women are described. Of course I'm just having a bit of fun here (don't get your ... in a twist as they say). But do bare in mind that this is a comedy and there is no reason for the lead person to ... well let's just say go complete psycho.
You may not be as understanding or at least may have thought that if someone is holding you back, messing up with everything you're doing (even if not intentionally, though how should you know?) ... you may think that the reaction would be more lethal.
But again, this is meant to entertain in a different way and it achieves that overall. The lead characters are fun to watch once you overcome that initial urge to ... well you know what. They grow on you and they grow on each other. Overall predictable, but still a decent effort to say the least (including flaws)