<human>: so here is the bottom line... 

my mom and dad left each other when i was 10 years old, back the. everyone walked over me i was afraid of everyone and everything, eventually my dad found a new girlfriend and they have been together for a few years now.

when my dad started moving in with his new girlfriend, the girlfriends youngest son who was 5 years older than me sexually abused me for half a year and i used to be able to surpress it in my memory but now i am confronted with it.

the son i am talking about has had alot of drug and criminal problems in the past but i was ready to leave it all behind and forget it all.

Now the girlfriend of my dad is having her birthday next week, i got an invite for it, but that is not my issue.

i never had a real girlfriend and 1 year ago i met the most amazing girl of my dreams, it's like we were made for each other and i love her with all my heart and will do everything in my power to make her life the best possible.

but, the birthday party invite said that we can both just come to it, but for the love of god i don't want to bring my girlfriend to that son that abused me for half a year, i know my dad will be really dissapointed that i won't come but i just can't.

every time that i think back about those times i start to cry and only my closest friend knows this story of the abuse and my girlfriend does aswell, i want to spare her any harm or fear or pain.

right know i just want to say that i skip the party and swing by another time when the son isn't there.

thank you for any help or replies.

Can you summarize the given text in a few sentences?
<bot>: party coming up but one of the people there sexually abused me for months and i don't dare to take my gf of 1 year to the party