wondering "what if"

i have a friend (for reals a friend not a make believe one and i am not feeling this, but i can understand) who has been married for about 10 years and she is feeling confused about how she feels about another guy. she wants to be his friend but she is feeling a lust for him. i understand that after a long time in a relationship, your thoughts do being to wonder, what if?
Everyone who knows me knows how i feel about cheating, i despise it. but now from what she had said her friend had told her, i do understand the other side, but a real fucken big but, if you have these feeling and you are at the point where you want to act on them have the respect for your partner to separate. cause which is worse to leave each other on some what good terms to go on with your lives or cheat on them, lie and break their heart.
I had told my husband this from the beginning if he ever wants to be with someone else he needs to tell me and we can divorce it is much better then being deceived. i have been cheated on many, many times and it hurts more and more the more you care about the person.
I think it is ok for her to be having these feelings, everone has fantasies or day dreams of being with other people. she has told me that she catches her husband all the time looking else wear. Everyone knows a man doesn't just look they think about sex constantly all day long. i think i read in a magazine a while back that every 3 to 5 minutes a man thinks about sex.
but if a guy is to look at her he gets all upset, why? cause he knows what he is thinking!!! the things those guys are thinking of doing to his wife he has no control over,no clue what their fantasy is and that is what makes him made. the stupid thing is that she doesnt acknowledge those guys looking at her or encourage them and he gets mad at her. what kind of bullshit is that i would think he would like to have a hot ass wife that guys are looking at. and the fact that he gets to go home and do what ever he wants to her and they cant nane nane poop poo!
well get back to the problem at hand she says she cant be friends with this guy cause the feelings a re getting stronger for him. but she is happy with her marriage and loves her husband.
what should she do?
Leave her husband on good terms and quit wondering what if and actually do something not expected of her or stay away from this guy and stay in her marriage.
i think fate put this guy there to answer her "what if" question. and now it is up to her to chose.
i was in her position about 10 years ago and i had to make the same sort of decision the " what if" was hovering over me like a dark cloud and i finally made a decision, i left someone and it was hard cause i had to stay there with him afterward cause i had no place else to go. it was the hardest 29 and half hours of my younger life. but it was what had to be done. and i am as happy as i have ever been.
i think no one should settle life is too short to settle. im so fucken happy i never settled a couple of times cause i would never had found my hubby. there are alot of "what if's" in my life and im glad that i chose the hard ones cause it lead me to him.
i dont know if this will help her or discourage her.
cause fate and karma happens for a reason, thats why i think we ended up being friends. The "what if" was hovering over her that day she emailed me for the first time and now a year later we are realy good friends, never met in person, but we talk all the time and we can tell each other anything.
so all i can say fallow your heart and dont worry all hearts heal. you do you and who cares what others think they will get over it. jump when you think it is time. there is that enough cheesy quotes for ya hehehe loves to ya girlie tommie