He laughs about the expression on Mayrina's face, but that's only after she leaves. I dare say that's not the mark of an evil person.
He makes a comment about hoping Lae'zel was going to give a show when she was talking to Zorru, but that strikes me as nothing more than commentary on her aggressive approach. Evil though?
Vague... that's a good word. It's seems that folks who think he's evil have this "vague notion" that he's evil, and most of that is almost certainly coming from him being a vampire, and so the suggestion that he's evil gets thrown about willy-nilly as if it's a foregone conclusion.
Jesus Christ. I can't even tell if you are serious.
Party control in Baldur's Gate 3 is a complete mess that begs to be addressed. SAY NO TO THE TOILET CHAIN