<human>: Can you provide a brief rundown of the text in within 3 sentences?

hi everyone,

this is gonna be one big rant. 
my younger brothers' [23] girlfriend [23] is one of a kind. 
at first i really liked her, but now i just can't stand her!

she really tries everything to break me [f 25] and my fiance [m 27] up. you wouldn't believe it. she tells him i cheated, that she saw me kissing someone else, tells me, that my fiance doesn't wanna marry me, but that he knows i want it, so he's kinda feeling forced etc. she even said that he had been trying to kiss her...

that's not all though. my brother is so madly in love with her, that he believes every little shitty story she tells. it's even gone as far as him not wanting us over at his place anymore, and avoiding us at family get togethers.... i tried to talk to him, but it's nearly impossible to have a normal conversation with him.

this shit is really dragging me down. the worst thing is, that my brother barely talks to me anymore. we used to tell each other everything, but now (if we talk) it's like "hey, how's work? the weather has been good lately" and he's also turned his back on our other two siblings...

please help. 

thank you,

needcandy
<bot>: my brothers [m-23] girlfriend [f-23] wants my fiance [m-27] and me [f-25] to break up....