Disclaimer: I get so much hate for this subject, so let's just start by saying that I do have other friends, and I have a friend whose been my right hand woman since freshman year of high school. So yes, I do have friends and I love and respect them dearly.
Whenever someone asks me who my best friend is, I always say my boyfriend is.
You can't even imagine how many dirty looks I get, or I get the statement: "Your boyfriend can't be your best friend".
This statement angers me, because it is just so inaccurate. In fact, it's actually better that your significant other is your best friend, and let me explain why.
My dad once gave me really good advice when I was sixteen, and I was crying over some guy I barely knew who dumped me after like 2 months of dating. He sat down on my bed, passed me a tissue, and said: Date and marry your best friend, because no one knows you and understands you like how they do.
Since then I made true, honest connections before really 'dating' people, which ended up giving me three long-term boyfriends who have changed and impacted my life: one during my adolescent years who helped me find out what love meant, one who came post-high school and taught me how to be in a relationship, and the one I'm in today that helped me realize how to love myself. Without their love and friendship in the relationship, I wouldn't be who I am today, and I don't regret a thing.
My current boyfriend of almost two years is my best friend, and I have literally no regrets about it.
He was there for me when a majority of my family and friends abandoned me, and he was the one to pick me up and dust me off. He was there when my mental health was at an all time low, and he became my sense of hope when everything just felt hopeless. He gave me a support system that I cherish, and gave me courage when I didn't think I could keep going.
With that being said, don't come at me with "you spend too much time together" or "your partner shouldn't be your best friend" because at one point he was all that I had, and I truly appreciate him for staying with me and loving me when I couldn't even love myself.
Now, our relationship is finally out of the honeymoon phase, but we still work as a team. We pay bills together, we are working on moving into our own home together, and even though we have different hobbies and interests, we do things together to make lifelong memories.
Again, I love my friends and my best girl friend will probably be living in the same old folks home with me as we bicker about clouds, but why would I want to not be best friends with my soulmate as well?