Modern AU - Tav and Karlach care for Dem's (@joasakura) "Cat" Lester (a rescue Gremiska) while he's away doing emergency rescue dive training up in Waterdeep. Tav may have forgotten that he's not actually a cat, but they have a good week regardless. Tav is willing to be patient letting him settle, but Karlach is eager to play and plies Lester with treats as per Dem's instructions. He is an extremely spoiled boy, and warms up pretty quickly (and is allowed to destroy some things at his leisure - though his favorite is Dem's old boot.)
Also, Tav and Karlach know Dem is a very protective dad, threaten to tattoo Lester, and get Astarion to work a little photoshop magic to send him this:
Dem absolutely flips out that "the tieflings have defaced my cat!!!" however, Astarion already gave Dem's brothers the heads up that this is a prank AND it was Tav and Karlach's idea (Astarion is already on thin ice with Dem.)
T&K send a bunch of photos to assure Dem Lester is fine, as he was threatening to hop back to Baulder's Gate and rescue his pet. They didn't mean to make his week more stressful but they couldn't help their nonsense.
(Also, being a vocal mimic, Lester learns some INTERESTING new sounds during the week - although Tav and Karlach swear they locked him out of the bedroom. It's only fair though, he's demonstrated some... interesting sounds himself to them already;
Tav "Huh, never knew Dem was a screamer. Should have figured."
Karlach "I don't think that's Dem... But I don't think Halsin's voice goes that high...")
