Anyone can wear out even the most sympathetic ear. I have friends that I love dearly but they malinger, pout, or continue to regurgitate the same problems on me - I have no issue with problems that a person is actively working on changing, or persistent problems beyond control that dog them (like my friends with ALS or paralysis, or serious financial problems not of their doing).
I think the key is whether or not you feel like you're being used. Is this person trying to work out a problem and it may be a little messy? Or is this person just griping about something over and over because they want someone else to listen to it? Big difference, IMO, between the two. One is malingering (I had a friend who made her occupation to break up and get back together with her boyfriend, and it drove me NUTS because she'd talk my ear off about it, crying, not doing a thing to change the cycle - frankly, she liked the drama.) One is just the luck of the draw.
Make yourself unavailable for those vampiring monologues. Or, just come out and say, "Pete and Repeat went out in a boat. Pete fell out. Who was left?" and let them get the hint.
A great deal of my friends are Fe (though I'm the only primary Fe in the bunch).2) Socializing: i end up making friends with Fe, but I am more apreciative of a good fight(not physical one), and i usually end up teasing and making fun of mostly everyone i could classify as a friend.
Goodness. The things ENTPs and I have gotten up to.3) i once met an ENTP girl, at first i didnt think much of her, but then again we didnt talk too much, but then we went on a date, and during the whole date i was like tottaly confused, it was as if my mind went click with every word she said, eventually nothing happened, but it was a damn strange experience, does that happen with every I(NF)J and E(NT)P encounter?
I've always liked their ability to take me completely off guard in a pleasant way. It's an entirely different yet symbiotic manner of thinking.