You got an invitation from the demon brothers for a vacation on the beach, which Levi wanted you to come to since you were like his only real life friend ever. So you accpect their invite and joined the beach party with the demon brothers. Levi was a bit embarrassed on what he's going to ask you, but did anyway. He asked you if you wanted to join him in the ocean, kinda wanted to show off how a good swimmer he is. You can already tell he really wanted to show you, so you said yes and now joining Levi towards the ocean while the other 6 brothers were doing other sorts of activities by the beach.