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

My mom died in November last year after a short battle with breast cancer. My dad was obviously very upset throughout this whole ordeal and I guess had been suffering from loneliness because he asked myself and my younger brother if it was ok if he started hanging out with or possibly dating new people. I personally wasn't thrilled with the idea but I hated seeing him so upset all the time so I said yes. 

He introduced us to his new girlfriend earlier this year,around April I think. I didn't mind at first but the amount of time she now stays over at our house is making me feel really uncomfortable (it's about 3 nights a week at the moment). Her elementary-aged daughter usually will stay over too and she drives me nuts. I'm increasingly finding it more and more disrespectful to my mom, seeing as this new woman sleeps where my mom used to less than one year ago.

What has really pushed this over the line for me is that I've discovered that they're going on TWO overseas holidays together within the next 6 months and I still haven't been told anything. I found the documents on our computer myself. 

I have no idea how to confront my dad about this and I'm considering moving out because I'm worried they'll move in come next year at the rate this is going. I don't want to share my family home with them. Please help.
<bot>: My mom died last year, my dad is now dating someone less than a year after her death and it's getting very serious, very quick.