<human>: Give me a shortened version of the text

My brother is 26, his girlfriend (36 with two kids from a previous marriage. imagine a five foot tall barbie with a mouth that never shuts.) he met this june is now his fiance as of this september.

my brother lives in the same house as me and my mother for workspace and free rent. 
she comes by often and somehow they can get into an arguing match that lasts over 24 hours, locked in his room only coming out to use the bathroom and maybe eat something. 

honestly I can paraphrase their entire relationship in the span of ten minutes, I can't fathom how they could have this much shit to argue about that it would last for this long. 

this kind of arguing match happens every. single. day. they're together. not joking. they tend to break up and get back together at least twice a month. 

it's either stemmed from one of them getting jealous of the other or some other shit and this woman won't stop talking. even when my mother and I told her she should leave before someone gets hurt, she'd sit there and keep egging him on. 

I haven't spoken to my brother in days because he's either holed up in his room with her or out of town with her. we used to be really close and now he hardly even texts me.
<bot>: my brother and his fiance are poison for each other. I as his sister do not know what to do. I can't let this get to the point where my brother might kill himself over this woman. this is destroying my family.