<human>: Can you condense the text into a few key points?

Because as a 20 year old adult, I feel like I deserve to have one. 

I have a close group of friends which happens to be mostly composed of guys. Myself and three of the guys have some time off work next week and decided we want to go stay in the mountains for a night or two. We're all home only for the summer and don't have a lot of time off.

As soon as I mentioned this to my mother, she reacted negatively. She keeps telling me that it's "wrong" and "just not right" for a girl to spend the night alone with a room full of guys. I have tried to explain that we are all close friends who have known each other for at least 5 years, but she won't have any of it. She keeps repeating how "wrong" it is. 

Keep in mind, I never asked her if I could go. I mentioned that I was going. I will also be paying for this entire trip with money that I earn at my job, so it's not like I'm leeching off my parents for allowance money like a teenager. 

I've tried speaking to her calmly, but she always ends up yelling and crying. Any advice? Every time we argue like this, it hurts our relationship.
<bot>: How can I, a 20 year old living at home for the summer, find a way to gently cut the apron strings with my mother?