The scene from the trailer.
If this was how her life ended. If this was how she died, then she was about to check off one of the things off of her bucket list.
(Her bucket list consisted of only one thing.)
She knew that she was unnecessarily dramatic and that the possibility of her death was very low or even none existent, but she did stupid and impulsive things when she was nervous.
(She literally never did anything impulsively, but she needed an excuse to do what she wanted to do)
So she took a deep breath and moved her hand to the face of the distressed girl in front of her, pressing their lips together.
Or the Au in which:
Clarke has a plan, Lexa is gay, Raven is an asshole, Anya hates everyone and Octavia is just along for the ride.