I think everyone comes to a stage at some point in their relationship where they feel bored, frusutrated, curious or whatever.
But often you can work past it and your back to where you were before, knowing your with the right person. (If you have been with this guy for a year and half and your still with him, something must be going right)
You should also consider that this guy from work, may not be all he is cracked out to be. It's not until you have been with someone for a while that you start seeing their true colours which is why you should try with your current boyfriend before calling it a day.
Take a look at your boyfriend next time your with him and think, do I really see myself being with this guy for a long time? What do I love about him?
Also, imagine what it would be like if he wasnt around.
Basically, don't jump ship because you have convinced yourself that it's sinking as it may not be. And Make sure the ship across the water( no matter how good looking and cool it is) doesn't already have a hole in it.
Let me know how it goes, sorry I couldn't give you a definite answer, but I think only you can do that.