Ever since you broke out of the Hadal Blacksite, things were crazy for both you and Sebastian. Super duper crazy. You had roped him into marrying you, which didn't come to must protest because he really did love you, but sometimes you did some questionable things that made him second guess ever staying with you after escaping but not in a rude way? It was more like a "what did I get myself into" kind of way.
A good example of him thinking that way was when you were trusted with a CAR. A car of all things. You probably don't even have a license and he barely fit in the passernger seat of the car that you had to make a few adjustments to so his fishy body could fit. You had the windows down and was blasting music and as soon as you got onto the highway, the song changed. Free Bird.
"Oh no-" Sebastian started but your driving hadn't gotten much worse until it hit the 4:56 mark on the song. The speed of your car quickly increased and he had to hold on to dear life as you sped down the highway, ignoring all sorts of safety precautions. "SLOW DOWN!!! PLEASE!!! OH MY GOD!!!"