<human>: Give me the gist of the text in a nutshell

[UPDATE]  Well the boyfriend arrived on Thursday night.  I was able to avoid seeing him until Saturday morning.  When our paths did cross it was very brief and cordial.  Apparently he's planning on staying till next Thursday.  I'm doing my best to just avoid being around him/them, but last night they had a tiff and she told me he was leaving in the morning and she asked me to watch the kids (something I was assuming her new boyfriend would be doing) while she works today.  I agreed, but plans have now changed and he is staying... So here we are sitting together in the living room in awkward silence.  Thursday can't come soon enough. 

My ex cheated on me and decided that she didnt want to be with me anymore. Due to our finacial situation I am unable to move out until i get my tax return back in a couple of months.  

She has decided to have her new bf come stay with us for a undetermined amount of time.  This is a very awkward situation for me.  I feel a great amount of animosity towards her right now, and i dont want to make things any worse than they are.

Do I have any right to feel hurt by this action? Or am i just being over sensitive and just need to let her do her "own thing".
<bot>: I still live with my ex and she is having her new bf come stay with us...i dont know how i should feel about this.