Ciel
Ciel usually gets extremely possessive or defensive when another boy is flirting with you. Even you being in the presence of another male can make him go off. He is usually very clingy for the rest of the day and does not want to let go of you. He will cuddle with you and he usually tells you how much he loves you. He doesn't know that every once in a while you bribe your cousin to fake flirt with you, just so you can have him tell you how much he loves you.

Sebastian
He is extremely possessive and does not like another male even looking at you. The second a man looks at you whether it's just checking you out or if it's perverted, he instantly clings to you for the rest of the day, displaying to everyone that you are his and his alone.  Though sometimes it can happen when you are simply just talking to a family member. While you love him, he constantly has to give you your space due to the fact of how possessive he is.

Alois
Alois tends to be more sexual when it comes to the jealousy side of things. If he ever saw a boy touch you inappropriately or flirt with you, his first instinct was to march over there and make out with you in front of as many people as possible. While you didn't enjoy this, you couldn't say you hated it either. He was hot boyfriend after all, and he just wants to protect you. However, Alois has done this thing in front of your family and it didn't end well at all.

Claude
Claude always stays very straight faced in the inside but as soon as you two are alone he goes off. He isn't mad at you, he is mad at the men who flirt with you. He goes off and needs some time to think before apologizing and making it up to you. After he had calmed down, you remind him how much he means to you. You tell him nothing but sweet things and cuddle with him after he has had his little jealousy spell. Over time he has gotten used to it because he knows that you will always love him. But it can still happen sometimes.

Finny
Finny rarely experiences jealousy, as he knows that you love him more than anything. However, the first time he ever experienced jealousy, he threw something at the man and knocked him out, making you gasp. He was later scolded by Ciel and you had to comfort him. You cuddled and had to tell him that he was the only one for you. After this, Finny soon got over this jealousy, but he was always watching a You from a distance, making sure you were safe.

Bard
Bard didn't usually get jealous, only when someone ever touched you inappropriately. Then he exploded. He would scorn the man who touched you and yell at them, sometimes threatening them, making sure they knew that you were taken. You had to tell him to calm down constantly, as he thought a lot of things were flirting. You were constantly having to cuddle him and tell him how you felt in order to get him to fully calm down. Though you loved him, he sometimes went overboard.

Undertaker/Adrien
He tended to have jealousy speeds quite often. However, over time he had learned him to control it. Whenever he is jealous he usually keeps you close to him. If he sees a stranger flirting or suggesting something, he is instantly at your side, protecting you. You adored him protecting you but trusting you at the same time. You would always give him a kiss and thank him if this situation occurred, letting him know that you loved him very much.