I want to date my best friend and her boyfriend, but I worry that's "messed up"

I think I want a relationship with my best friend and her boyfriend. Am I messed up for wanting that? We all get along so well and I care about both of them so much and I feel fucked up for wanting to be with them that way. For wanting to intrude on their relationship. How do I stop feeling this way?

You are not messed up or fucked up. You are having pretty normal, natural feelings of intimacy for people you are intimate with! Caring about people so deeply that you want a new framework for your relationship is not, in general, a bad thing. Wanting more true, real ways to express and live out your feelings of love and care is not "fucked up."

We live in a world that prioritizes certain types of commitment over others. We feel like we can ask things and expect things of people we are "dating" but not people we are "friends" with. So there is a kind of insecurity that comes from not having a "dating" relationship, and I get it!

The only way that it would be "messed up" is if, in acting on these feelings and desires, you violated boundaries. If you have genuine reason to believe that your friends would be really threatened or put off by you broaching the topic of a shift in the relationship, it might be best to drop the issue. If you don't, it's worth bringing up! Let her know how you feel, what your ideal relationship framework would be, and why.

If she says she's uncomfortable with that, and you keep pushing or trying to convince her to see things your way or trying to underhandedly act as if the relationship has changed and thus manipulate her into it - that would be "fucked up." But all you've done now is have deep feelings for people you're close to, and want to live out those feelings in a more authentic way. There is nothing wrong with that!