I don't think.. Pulling out your sword will do the trick. That is kind of lewd and abrasive. And you might turn her off! Plus catch a charge... Let the game come to you... Use your mouth piece. Get inside her head. And last respect her boundaries.
Take your co-worker out to lunch or for a drink before you pull out that wonderful cock of yours. That's what my BBC boss did with me, his hotwife secretary. A little courtship and flirting goes along way!
If she is married and her partner is cool with his wife having a boyfriend, you are well on your way. Enjoy lunch but don't rule out a drink after work next time. Take your time, go slow, make sure you both want and need this.