i have a crush on someone

she is my p.a. and we have been working together for over 10yrs already.......she is beautiful very lady like and I have a serious crush on her.......the only thing is I am married with kids and so is she .....I need some advise to what to do from some ladies.....I want to tell her but im scared and a bit shy but its eating me up inside .......what do I do ?