^ lol
A fan asked Tiffany Vogt about this scene (Bellarke and Jaha). This is her answer :
And I need to share this, Tiffany again, not even spoilerish but...
Spoiler:
Ok Tiffany is just plain losing it on the Bellarke !
There is only one person that Bellamy could be in love with since he landed on earth.
ETA: Thanks for the explanation April !