There are on occasion some happy endings but more often than not, serious regret and pain over hurting those you claim you love. You could really do damage to your kids and your husband. Not to mention I think I read he is married too? So, its two families you will devastate all for a roll in the hay, so not worth it.
If you really don't think you love your husband anymore, that is a totally separate issue and one you really need to be truthful about. It is so normal to think or even fantasize about being with someone else when you have been married so long. I saw an old college flame at a recent reunion who if possible got even better looking than when I dated him AND hes not married, and believe me if I wasn't married, I would have been all over him but the thought never corseted my mind, I just admired from afar
Have fun in your mind and play out all the scenarios you want/ need to but honey don't act on it...you will likely regret it for the rest of your life.