(Yandere Riddle x Rose. Rose is the headmaster's adopted daughter. So while he's gone away on vacation or whatever she has to watch the school and students but one student favors her and obsess over her and will try, do, or use anything to make her his.
Riddle grown a fondness for her and plans on using everything to his will)

While Rose was walking around the school making sure all the students weren't hanging out during the school festival. Each student have to spend time with the ones they love to see if they'll last or not or get married but sometimes these events can get deadly and fetal real fast.

Just as she turned the corner she saw Riddle standing there with a little pink bird on his finger "Hello my beautiful Rose come looking for me?"

"No I came to see if there any students trying to skip the festival and go to the sex part that's been happening each year." She said Coldly. Riddle has been trying to hook up with her for at least two years. "Well I'm here..shall we?"

"No." She walked off as he looked at her then placed on her a collar the cancel her powers "I wasn't asking you if we could I'm telling you.. I know we've had our differences but at least let me make it up to you~."

She tried to run but she's been in heat for too long "Ah..your in heat no wonder you've been trying to run too bad I'm going to make sure that your mine."

She went out as if she was under a spell and that spell was heat.
Riddle took her to his dorm room and locked the door even though there was no one there. He took off her clothes. "You see my power doesn't also cancel your magic it can bring out the heat you've been feeling for a long time and now your a mess."

He stripped as well opening her legs "I love you Rose." He said in lust with hearts in his eyes as he went inside her "Ahh~! Rose..oh Rose!" He thrust inside her pussy she began to feel like she had no control over herself "Oh Riddle Riddle!! More more!"

"Ahh yes yes oh yes!"  "Rose I've been waiting for so..long to have you!" He thrust faster and harder "Ugh! Fuck right there do you like it when I hit your little sensitive spot right there baby?" He wrapped his arms around her neck "Ahhh oh my god my mind is blank!" He said going faster "Riddle your... going to break me!"

Before she knew she came so did he.

Later

They went at it again making this their 5th time "Ahh fuck your ass is so tight Rose "Riddle please don't..not there!" "But you won't let me go you like it I can tell you naughty girl, you can't hide your heat from me anymore~." He licked her shoulder and neck biting it as well. "You are so good Rose~! I can't control myself I must..cum...now...ohh fuck tighter squeeze my dick harder!"

Then they went at it til dawn

"Oh Rose you like getting your pussy pounded huh?" "Yes Riddle yes I love it!" He stopped pinning her against the wall kissing her with his tongue inside with hers "I want you looking at me as I make both of us cum."
He put her leg on his shoulder and began thrusting roughly "Ahh fuck Riddle please.. everyone is going to hear!" "So? Your mine and mine.. alone- AHHH!"