Dean - Already knew when you met.
Sam - Already knew when you met.
Castiel - You were a waitress...Dating an angel. The thought didn't completely process until a week after he told you. When it finally did sink in, you shouted 'We are never having a kid!' for the sake of your own life. Castiel simply nodded, not too fussed with the condition. He didn't even question why you brought up kids when you had only been dating two weeks.
Jack - You thought he was a regular angel after you met his father, Castiel, who was an angel. You didn't understand the whole vessel thing at first, so you figured Castiel banged another angel and had Jack. After Jack explained everything though, you decided to research what he was. You once asked why he wasn't a giant like stated in the bible and he replied 'Lucifer was only above average height, and my mother quite short. I'd imagine I couldn't be a giant like Sam without Lucifer using him as a vessel and conceiving me with a tall woman.' You didn't bother bringing it up again.
Charlie - Your girlfriends a hacker? All you could think was how sexy she'd be cosplayed as Natasha Romanoff.
Meg - You knew after your first meeting. Let's just say - you were a hysterical mess of swears and had to be restrained by her. Yeah, not your proudest moment. You soon claimed though and was glad you weren't crazy.
Garth - You were shocked. Monsters? Ghosts? Demons? You thought he was crazy. After you got over that though, you demanded he teach you how to hunt so you could help him and keep each other safe.
Gabriel - You knew he was magical when you first met. But an angel? All you could do was laugh at the image of Gabriel in all white, tiny wings, a halo and harp. He must of read your mind because he looked like he instantly regretted telling you. 'Choir Boy' was his nickname for the next month.
Balthazar - You were tipsy at the time he told you. You simply stared and bopped his nose, saying he'd be a cute angel. He seemed a bit miffed by the 'cute' part, but he did agree with him being a 'fine angel'...You also then asked if it was sacrilegious to fuck him. His laughter didn't die down for a good ten minutes.
Benny - You had an idea he was for a while. It wasn't until he started drinking out of a blood bag in front of you that you realised he truly was a vampire. It didn't phase you much. You felt safe with him, monster or not.
Lucifer - In 'How You Met'.
Chuck - You didn't react well. Your reaction will be displayed in the 'Break Up' chapter.