Crushes can occur though you are in a perfect relationship or marriage. Nobody can be sure when it happens. However, we can handle it.

I agree with Scotty if they are single, and you are single, let them know. But in some cases, people you have a crush on might not like that. They feel offended, think about how they feel before you do it. And please choose the right moment, the right way, somehow subtle, to express your feeling.

If you are in a good relationship, as I stated, please don't cheat on your partner. Or if you have problems with your boyfriend/girlfriend, just deal with them to find out the solutions or break up before falling in love with your new one. Let's think about if the new one can make you happier, or "the grass is always greener on the other side of the fence"

Hugs to ya