I have a boyfriend but am still crushing on someone else

The new guy at work — what a catch!   
He’s cute, funny and so considerate. you find yourself passing by his desk more often, exchanging “hilarious” smiles and glimpse, wearing lip-gloss for the first time in years, trading your standard work pants and cardigan for flirty dresses and upping your hair game .

If you were single, all of these things could signal the beginning of a fun, flirty relationship. But you’re not single, you’ve got a loving committed partner and you want to keep it that way — the question is how?

 Here are 5 tips to help ensure that a harmless crush doesn't affect your committed relationship (#2 most importantly).
1.  Remember that it’s natural
Though you may think you’re the worst wife/girlfriend in the world for even thinking that someone else is funnier, cuter or sexier than your undisputed one true love, the truth is that you’re not evil, you’re just human. In fact, you’ve only succumbed to the same natural phenomenon as millions of other good, decent men and women.

“Developing a crush on someone other than your long term partner is normal,”
“Just because you are in a relationship doesn’t mean you suddenly stop noticing beautiful people. Crushes on bosses, coworkers, cute coffee shop attendees, waitresses, neighbours and anyone else you come into contact with on a regular basis is bound to happen, and that’s OK.”

2.Consider Commitment:
While a heavy commitment isn't always the norm for teens and young adults, if you do have this type of relationship, having feelings for another guy is especially troublesome. Unlike a casual relationship in which you and your guy hang out with friends or spend most of your time with your social circle, a committed relationship requires a promise of fidelity.
Having feelings for another guy while you're in a committed relationship means deciding whether to break things off with your boyfriend or ignore your crush. Consider whether your commitment is something that you can continue to carry on. If not, end things before you become unfaithful.

3.Honestly Speaking
If your boyfriend trusts you -- and in a mature relationship he should -- having an interest in someone else may violate his trust, and acting on your crush definitely isn't being honest with your boyfriend.
Dishonest behavior is likely to ruin your relationship in the long-run. Don't lie to him about your love interest or go behind his back and cheat. Instead of lying, be straight with your guy from the start. This doesn't mean that you have to tell him every time that another guy turns your head. Instead, if you know that you have real feelings for another guy, don't keep your mouth closed or lie to him about it.
4.Have control: Fantasies are fine and so are butterflies in your stomach when you’re in the presence of your secret crush. It’s how you behave in the face of temptation that reveal your character.
“Butterflies in our stomach that jump and flutter when they enter the room isn’t something that can really be controlled. What can be controlled are your actions,”
“If you are making regular coffee dates with your coworker crush because you just want to spend time with them for example, then you are beginning to cross that line between a normal crush from afar, to a slippery slope of emotional or physical infidelity.”