People who are married are wed, not dead.
There will be crushes, infatuations, attractions. It's not earth shattering. It's not a rare meeting of "meant to be". It's not an infallible sign that your relationship is fundamentally flawed. Romeo & Juliet do not need to eat their hearts out, because to the people noticing, and some will probably have noticed, it will likely look more cliched & unprofessional than exciting & romantic.
You deal with it. Every time you tingle, flutter, perk up at an idea to do with him - you shut it down. So if you find yourself picking what to wear carefully to look attractive for him, catch yourself and put on the skirt that doesn't suit as a kind of negative reinforcement. Ditto hair, make up, anything else meant to garner sexual attention from him. Same goes for engineered chats, visits to the coffee machine when he'll be there etc. Catch yourself, remind yourself you aren't 14 anymore... and do the opposite. Aim for massive "wide berth" rather than fluttery "wide eyed" where he is concerned.
There isn't enough sexual fission in the world that could make up for your children's devastation if you deliberately take a sledgehammer to their happy enough home.
And it will be deliberate. Even if you didn't think anybody would find out, Even if you didn't realise you'd cross any (rather mobile) lines in the sand until you did. It would be deliberate becuase when you pick your thrill over your family members, despite knowing the risks to them, you are making the clear, undeniable choice to gamble with other people's short and long term happiness.
You are in complete control of this. You are driving it. There are no little people inside you making you do what you don't want to do. The bloke has not taken the driving seat of your central nervous system. So work out who matters most to you, your inner teenager, or the people you chose to commit/create. Bear in mind if you pick them, then just you will be down/struggling for a short while. But if you make a priority of your wants over their needs, everybody, including you, will feel godawful for potentially a very long time indeed. If you have ever thought of yourself as somebody who would die for their children if needs be, then this is the time when you get to test the theories you hold about yourself as a mother. What price actual death if you aren't prepared to take on mere short term, emotional discomfort via the denial of pleasure, for the sake of avoiding an emotional bombshell dropped on their lives ?
Next time, do the avoidance and "punching it back down" at the first seedlings of a crush. It's far quicker and easier than chopping it back after you've been chucking gro-more at it for a few weeks.
You'll live. You have an infatuation and a tingle, not the romance plague 
And coming through the other side to the point when you realise just how much power you have over your own feelings (ie choosing not to whip them up into a frenzy, but knocking them back into order instead) is quite a revelation as to how much we control things we sometimes prefer to think of as having "just happened".
It's a power that can be used for making your life healthier and happier every bit as much as it can used for letting self off the hook by viewing actions as accidental rather than purely selfish. Knowing you can control how you react when you feel whatever it is you are feeling makes it much harder for anybody to make you feel helpless and held hostage by your emotions in the future.
As a pay off for the angst and irritation of losing the "I can't help it, twas BIG FEELINGS fault, not mine !" card .... it is worth every shred of effort involved in getting there.