Why does my family keep shipping me with my boy best friend???!!

OKay, so for the purpose of this rant, we're gonna call my guy best friend, babygirl. So me and babygirl have known each other since kindergarten and we used to hate each other, but then we got rlly close about a year ago through dnd. We have a running joke that he's my platonic trophy wife, even if he's 6'3 at 14, therefore the babygirl thing. We're super close, we make dirty jokes together, hang out one on one, I steal his hoodies sometimes, but we both agree that we aren't attracted to each other and aren't interested in a relationship with eachother.

Now the thing is, I do realize that we low key kinda act like a couple sometimes, and if I look through our texts, ur gonna think we're hooking up. We arent anything more than friends. Yet people ship us, a lot. Our mutual friend's grandma thinks I'm babygirl's girlfriend, my little sister and her entire friend group ships us and one of them wrote "L+(babygirl's first name enitial)" on his arm in orange sharpie and it wouldn't come off, our other mutual friend and her girlfriend who doesn't even go to our school even thinks he likes me. 

I know for a fact that he doesn't like me like that cause I had a suspicion that he did at one point, so I checked with his best friend of 10 years, and babygirl doesn't like me romantically. 

My parents also ship me and babygirl. My mom is better at keeping it more enternalized and actually rlly loves when I hang out around babygirl cause she trusts him and he's nice. But my mom has given me speeches abt how she wishes we werent so brother and sister like cause if she could choose a boy for me to date she'd choose him, she thinks there's some underlying attraction there and if we decide to stay friends shes cool with that and if we decide that we like each other then great, and so on.

My dad is the worst tho. For context, I have a lot of daddy issues I'm not quite ready to talk abt on here but yeah... Anywho, he ships us outright and makes me and babygirl's friendship the bud of every joke. It started when height was brought up at a family reunion, and my dad brought up babygirl cause he's taller then my dad, then my dad was all 'oh, he acts like he likes you!" and my entire extended family was on his side and I had to spend 20 minutes convincing them that we're just friends. That was my cousin's new fiancee's first impression of it. Since then, he's brought it up at two more family gatherings, convinced my extended family on both sides that we're a thing, and made many comments such as 'oh, Londyn went to a movie with a boy", the boy being babygirl, "are you texting boys?", and a lot of other ones. I've told him to stop countless times, cause honestly, its making me uncomfortable, affecting my already crappy relationship with my dad, and its pissing me off. 

Why cant a man and a women just be friends?!