Rejection, basically, once someone says this to you, you're thrown into the friend zone
, this is a hard place to get out of and you know you fucked up somewhere if this is where you end up.
Fairly good looking guy meets fairly good looking girl, a few weeks later they can't stop talking to eachother, the guy is really into her and thinks she feels the same way, he is about to say something to the girl, meanwhile the girl is thiking "great, another friend" the conversation goes like this-
guy-i've been having a great time with you lateley.
(at this point the girl thinks "wow, we are so much alike", the guy is thinking "thats a good sign")
guy-i kind of have a confession to make - i have felings for you
girl-i'm so sorry, i just see us as friends
(at this point, the girl is thinking "i see us as just friends, i'm not into you in that way" the guy is thinking "for fuck sake!")
so, going by that example, the guy got thrown into the friend zone because he went about getting the girl in the wrong way, now they may still be friends, but there will be tension for a long time, other typical reasons why you might hear these words are-you're ugly/have a bad personality/the person who says this isn't single.
1-A boyfriend who is overly emotional (bordering on women on period emotions).
2-When a guy likes a girl but she likes him enough to have all the fun of a relationship with him, minus the sex or making out, this is a derivative of the friend zone but is not quite as bad as the man actually means something to the girl and there is or was a degree of attraction, the way to get out of this is to avoid this or to get out of it is to make half the relationship light flirting and half emotional support and caring.
1-John started crying with happiness when him and Claire were on a romantic date, he is such an emotional boyfriend.
2-Daniel likes Emily and she likes him to an extent but dosen't tell him, so that she can get all the emotional support of a boyfriend minus the commitment and other problems, he is her emotional boyfriend and needs to start flirting with her