Having a crush on a guy while being in a long term relationship

I have been with my boyfriend for 2.5 years. Everything is good for the most part, I mean there was one time recently that I almost ended it because he had been lying to me for over a month... but other than that I love him more than anything. 
I got a job back in february and have found myself falling harder and harder for the night manager. I've told this guy that I like him & he likes me back & we hug every shift, but I can't bring myself to end a 2.5 year relationship just to be with a guy that I've only known for 3 months. My boyfriend and I have been through so much and we have grown so much together, but this other guy... omg he's so amazing. 
I really don't know what to do! End it with my boyfriend and go for the new guy? Or leave the new guy in the dust and stay with the guy I know.