Sonfic time! Italics + bold are the song lyrics. The song is I wouldn't mind by He is We. I know Ciel is a bit (a lot) out of character lol 

"Come on, (Your name)!" Ciel said excited as he could be. 

"I'm coming, I'm coming!" You said. (Not what you're thinking little nasty)

Ciel was currently dragging you somewhere. He had parked his car in a parking lot a few blocks back, and now you both were just walking through the city towards the woods. You both continued walking (you being dragged more than you walking), and came to a clearing in the woods. 

In the center of the clearing was sitting Sebastian with an acoustic guitar. You stopped and Ciel went to the center with Sebastian. Sebastian started playing the guitar, and Ciel started singing. 

"Merrily we fall
Out of line, out of line
I’d fall anywhere with you
I’m by your side

Swinging in the rain
Humming melodies
We're not going anywhere until we freeze
I’m not afraid, anymore
I’m not afraid." 

You remembered when you both had first met. Ciel said he was afraid to fall in love because everything he had loved was taken away from him. He didn't want to lose anything anymore. Eventually, you both started having feelings for each other, and you reassured him that he wouldn't lose you.

"Forever is a long time

But I wouldn't mind spending it by your side." 

You smiled at the lyrics that he sang. You wouldn't mind spending forever with him.

"Carefully we're placed for our destiny
You came and you took this heart, and set it free
Every word you write or sing is so warm to me, so warm to me
I’m torn, I’m torn to be right where you are

I’m not afraid, anymore
I’m not afraid

Forever is a long time
But I wouldn't mind spending it by your side
Tell me everyday I get to wake up to that smile
I wouldn't mind it at all
I wouldn't mind it at all

You so know me
Pinch me gently
I can hardly breathe

Forever is a long, long time
But I wouldn't mind spending it by your side
Tell me everyday I get to wake up to that smile
I wouldn't mind it at all
I wouldn't mind it at all.."

He suddenly was handed a black velvet box by Sebastian after he had strummed the last chord on the guitar.

Ciel bent down onto one knee and opened the box revealing a beautiful sapphire ring. 

"(Your name), will you marry me?" he asked with a faint blush appearing on his cheeks.

You nodded your head with happy tears streaming down your face.