Lyric discussion by instalux 

Cover art for Sweet Dreams, TN lyrics by Last Shadow Puppets, The

It's about his current girlfriend, Taylor - almost an ode to her. She's from Tennessee and has a septum piercing. Seven years of bad luck meaning it took him a handful of past girlfriends over the period of 7 years to finally find her.

Song Meaning

@instalux 7 years of bad luck is the superstition that if you break a mirror you'll have bad luck for 7 years. I think it's more a reference to the wild sex where they'll break a mirror by crashing against it, but the sex will have been so good it won't bring them bad luck.