0
I'm not sure why you would want to go after someone who is already committed to someone else and clearly unavailable. My advice would be to accept that she wants to be with someone else and move on. The consequences aren't just on her side, but also on yours. If you can pull her away from one committment, who is to say that she will remain committed to you? And, depending on your relationship with your conscience, you may find that breaking up a marriage causes you feelings of guilt.
However, since the question should be answered... seducing someone who is married is not too different from seducing someone who is unmarried. You hang out, flirt, and see if they respond, and if so how. Then you decide, together, how to move forward. The main difference is usually keeping it secret from the spouse of the person you are seducing... and the worry that the other person values that secret more than they value you, and having to sleep alone, and the very real way that you are second string.
