One Last Coin

This is an excerpt from one of my short stories. I'm looking for advice on how I can make this more detailed and if there's any other way I can make this better in general.
Marie smiled and placed her hands gently on the sides of his face and gently kissed him. Vincent smiled and returned the sweet gesture of affection. When the kiss ended they stared at each other smiling for a little bit when Marie said, “See? It's nice and quiet out he-”
She was cut off by a blade piercing her stomach. Vincent's expression was cold when he ripped the blade out of her. Marie looked at him in pure shock and looked down at the blood pouring from the wound in her stomach. She looked back up at him with confusion written in her eyes as she choked out, “W-why?”
Vincent let out a cold chuckle and said, “You know I really love this time of year. The chilly, cold breeze just warms my heart.”
Tears poured of her eyes as she watched her life blood flow out into the pristine snow. Vincent knelt next to her and said, “Oh don't cry Marie. You'll be okay in a few minutes.”
She looked at him with a hurt expression on her face and she whispered, “Why? I t-thought you loved me..”
Vincent laughed and said, “Love? No. I've spent years practicing on how to play the role of a helpless man when I learned that my sister was planning on leading a rebellion against me. You were just a pawn in my plan. I need a way to work myself back into society and eventually back into my throne. When I met you and Oliver then I knew how I would work my way back into society. Once Oliver's dead then I can take over the tavern. People will feel sympathetic to my plight and eventually I'll be able to convince them to help me rebel against my sister.”
Marie choked and coughed up more blood and let more tears fall from her eyes. She stared at Vincent then managed to say, “B-but I loved you......”
Then she fell limp on the ground, her crimson blood pouring out into the snow and permanently staining her skin. Vincent stood up and gingerly cleaned the blood off of his sword and said, “Yes. I know you did. None of this would have worked if you didn't.”
He took a deep breath and sighed happily.