I Choose You (Sequel to 'I Hate Ultimatums') ( Saiki K x Fem! Reader )

day 3

The birds sang outside your window in a chorus of beautiful chirps. The sun had invaded into your room through your open curtains and you woke to it's shining glare onto your eyes. You woke up with a dull and fading headache, unable to recall the events of last night.
Woah. What the hell happened last night?

Your phone lit up with a message.
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Nothing extravagant like yesterday or the day before. I guess I realised that the cliché flowers, teddy bears and fancy dinners works well to impress girls but it's only temporary. I thought I'd do something simple and catered to you and only you. Meet me at the park in 15 minutes? :) (also I hope your headache from yesterday is better. A bit sad that it ruined the dinner but I'm glad you got home to rest) - Kusuke
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You were confused but also slightly excited.
I guess I had this bad headache yesterday too so it messed with my memory.
You brushed it aside and looked forward to what Kusuke had in store.
Catered to me and only me, huh?

*

"Yesterday I realised that I never even had a chance to win this challenge. I lost from the moment it began. I took her for someone who was only into you temporarily. I underestimated her feelings for you, little brother."
Kusuo didn't move his deadpan face at Kusuke's explanation as the two brothers sat in his room.
I know that already.
"That being said, I think I could fall for her!"
Eh?
"The love she has for you! I want it! Never have I seen such genuine affection." He outreached his arms as he continued.
"If only she'd psychoanalyse me the way she's done you. If only she could point out the things I do that make her happy! If only I could be on the receiving end of that pure, raw love." He brought his arms back, embracing himself as he reminisced his yearning.
Okay, you're a yandere. We get it.
"As a genius, it's impossible to find love because I don't even believe in such a thing!"
He's still going?!
He continued to ramble about love and why he had never experienced it and why he had no interest in it until Saiki changed his expression to his annoyed face.

"But of course. Her heart belongs to you and it seems like no science in this world can change her views. The final day and my final gift to her: meet her at the park in 15 minutes. I'll see you again when I'm back from England." Kusuke smiled, head down and exiting the room with his suitcase in hand.
Good grief.

*

When you arrived at the park, you saw Saiki sitting on the bench where he confessed. Your lips instantly curled up, rushing to him. You sat on the edge and slid across the smooth wood of the bench to bump shoulders with him as you giggled.
He turned to face you, resting his hand on your head as you looked up at him.
"Will you be my girlfriend?"
Huh?

It took you a minute to process what he had said.
"I will! I promise to be the best girlfriend in the world!" You hopped of the bench, leaning down towards him. You held out your pinky, a big smile on your face as you waited for his.
He looked to the side, a pink staining his face as he outreached his pinky interlocking with yours.
And I promise to be the best boyfriend. → you

The colour of your cheeks mimicked his and you looked away, flustered again. A smile plastered on both your faces.
My boyfriend is a psychic.