My Players Are Overflirting With Every Single Monster They See

My current campaign consists of 4 characters with high Charisma and Persuasion. They were tied up in a Quaggoth (https://forgottenrealms.fandom.com/wiki/Quaggoth) lair, getting prepared for a feast, when our Rogue rolled for seduce, and got a natural 20. The party escaped and our rogue began a relationship with the Quaggoth (he sacrificed himself for her later). Soon they all began to flirt with every sentient monster ever.

How in the friggin' world am I gonna deal with this?