Which leads to the question: WHO BANGED OBI WAN KENOBI?
On the off chance it wasn't you, I might have another answer: In the Clone Wars animated series, which I think Disney wants to keep as being part of the official canon, Ol' Obi has an unspoken love (crouching tiger hidden dragon style) with a Mandalorian Duchess called Satine Kryze. It references the relationship between Anakin and Padme, and shows what would have happened if They'd remained professionals and didn't act on their emotions. It was a cool and kinda heartbreaking side plot. According to Wookieepedia: "The Republic sent two Jedi Knights, Jedi Master Qui-Gon Jinn and his Padawan, Obi-Wan Kenobi, on an extended mission to Mandalore. They spent a year on Mandalore protecting the young Duchess, from the hostile insurgents threatening her world, and Kryze and Kenobi grew close to each other. Despite his feelings toward her, Kenobi continued with his training and was reassigned. Kenobi later stated that had Kryze asked him to stay with her, he would have left the Jedi Order to be with her."
Yes, I'm a nerd.
And I don't recall this specifically, but apparently the lighting on Ren's face goes from blue to red as he does the deed.
The red light was always there. He was lit red, from the hall they were in, and blue (or actually probably white) from the dying sun outside, that shines in like a beam from behind Rey and Finn. When the sun dies, because the planet ate it up, the light behind Rey and Finn dies out, leaving only the red light from inside the hall. This is of course perfectly timed with Kylo not handing over his lightsaber as much as we first thought.