Someone started a sin thread a few weeks ago but it was just full of weird eating habits... Couldn't help but notice far too many people had juicier sins to share... what better place than to people who know nothing about you? No judgments here guys, we're all psycho's in our own little way 
Mine is last year I was working on a well known tv show, and despite being in a (boring), I had a HUGE crush on the floor runner, so everytime I needed to go anywhere I would seek him out for a lift, felt guilty about it for months and months until aforementioned relationship ended AFTER filming finished and I wish I'd ended the relationship sooner!!