I'm having nightmares from sleeping with the enemy

Keri Hilson and "Energy" have really put some words and sounds to this "thing". I can't exactly describe it as a relationship, as it doesn't really warrant that title. However, I've been in one of those one-sided situations where you working overtime for some part-time shit. I've been in both roles. She really said it there. The lyric "I'm having nightmares from sleeping with the enemy" speaks to me in volumes, as I'm messing with an ex now. He thinks it's going to muster up some of the old, but he's wasting his "Energy". When's the last time you wasted some "Energy"?