Certainly it is morally problematic to nurture romantic attraction for a married man, especially so when a married woman is giving to married man what rightfully belongs only to her husband and accepting from him in return the “stolen goods” that rightfully belongs only to his wife. It also places the man and woman involved in a near occasion of sin because there will be a temptation to find solace in each other whenever your own marriages hit turmoil (which is very likely already the case when married people nurture romantic attraction for someone who is not their spouse).
Not only should these people not only have no physical contact, but they should have absolutely no relationship at all. If they are in a situation in which they are thrown into a relationship with each other (such as working for the same company), one or both should seek a transfer or another job. They should also realize that what they are feeling is not true love because true love wills what is best for the beloved; what they are feeling is the emotion of romantic attraction, which can fade if given enough time and distance.
