For the duration, you have advantage on all Charisma checks directed at one creature you can see that isn't hostile toward you.

When the spell ends, the creature gets a Wisdom saving throw. On a success, the creature realizes that you used magic to influence its mood and potentially becoming hostile toward you. A creature prone to violence might attack you. Another creature might seek retribution in other ways (at the DM's discretion), depending on the nature of your interaction with it.