a friend + married friend are totally head over heels, but cant express because 1 is married, im sure married friend would leave partner if knew for definite friend is interested. what advice should i give, they're perfect for each other. how can they safely express their feelings?
Stay away! you're going to come off like a shit if it works and a shit if it doesn't. let them do it or not if they feel strongly enough.
Try to stay away from the situation but if you must give advice, tell your friend that not to try and get in a relationship with the married person. They might be perfect for eachother but even if the spouse of the married person isn't kind to your friend's lover and if the spouse is a jerk, and unloving then the the other should leave or divorce before getting in a relationship. Anyway you try to justify it, it is still cheating and no matter the situation, some one gets hurt. Someone's gonna get burned and a lot of times, the person getting burned is the one who is in love with the married person. Tell ur friend to wait a bit cuz it's still cheating, cheating hurts everyone, and it is human nature to contue the same behaviors so most of the time if ur in a relationship with someone whose cheating, they'll cheat on u after they leave that other person.