She is a princess and deserves the world.
She is the only person I trust completely.
She is the only person I know I can lean on 100% if I've had a bad day.
She is one of the few lights in my life, and if you ever make her go out or even dim, I will make her brighter than she's ever been to shine past the aches you caused.
If you don't treat her how she deserves to be treated, I will make your life miserable. I will make you regret everything you'd ever done to make her cry, scream, second guess herself, second guess her choosing you... I won't back down. I will not give up until I make her see you're not good enough for her if you even think about betraying her for a single second.
Now, while you have not messed up, I am still always watching. I want the best for her. You should, too. She's been through a lot. She needs something constant. She's needy. She's emotional. She's insecure(aren't we all?), but she doesn't show it right away. She doesn't like admitting any of it either, but it's part of who she is as a person. She can't help it. So, you better not think any less of her as a person for being that way.
My best friend is the most important person in my life. She's not herself if you're hurting her, and I can see that. I can see everything. She tells me everything. She lets me know how you're doing, and if I hear one single thing that's bad, I'll start doubting you as a person. I'll watch more closely. I'll be the hawk to your mouse. I'm not afraid to speak my mind about her partners. I've done it before. She's done it for me.
Her and I are super similar. I can tell when she's had a bad day just by the pictures she posts, the way she types a reply, her choice in alcohol for the night, what she's wearing. I know. She knows me, too. Knowing her is knowing me. So, why wouldn't I take it personally when someone is hurting her? You're hurting me, too.
No one is perfect. You will mess up somewhere along the way, but how you compensate for what you've done is going to show me just how much you truly want to keep my best friend in your life. How you make her smile again after making her cry or scream is going to demonstrate just how much you actually deserve her.
I am over protective as she is for me. She's told me straight up when I've been at the end of relationships that I'm worth more than what my exes made me feel like, and you better know that I will be doing everything in my power to make sure she never just settles for someone who treats her like crap... because it "works." That's not fair to her.
I will know how she feels about you. We tell each other nearly everything. I will know if she's hurting, and if you know you've given her reason to, you won't like me. I promise you that. You will not like me.
She's a princess, and she deserves the world. Give it to her.