Why did my dad ask my guy friend if he had a girlfriend? Why couldn’t he kept his mouth shut?

My guy friend and I known each other since first grade and he’s kept in contact with me for years which I'm grateful.
Yesterday, dad had to ask, “So do you have a girlfriend?”

He said no and my dad was like, “Why not? There’s a good woman right in front of you! Pointing at me.”

My guy friend got nervous and said I'm his girlfriend. My face got warm with embarrassment. My parents were like, “Oooooooh!”

I was like, “Okay I had no idea we were a think.” Sarcastically.
His mom said, “Well you do now. You’re stuck with him now.”

My dad said, “Hey its all good! You got yourself a REALLY good woman. She’s very smart and girlfriend material.”

It was just a joke! My mom was like, “You don’t need to look anymore because you got yourself a boyfriend.” And she laughed. I was like, “Mom please. We’re just friends.”
Then she said, “Oh come on! It’s so OBVIOUS that he likes you. I’ve seen the way he looks at you. I remember he took you to the school dance THREE TIMES!” You said yes every time.” I said, “The second I meant to say no I wanted to go with other guys but they already had dates and he invited me the last time.” Then mom said, “Yeah but if he ALWAYS asks you then he’s obviously into you. Besides he treats you so much better than that loser boyfriend you had. You outta give him a chance sweetheart. He may not be your type (my type is fit, lean), but he’s boyfriend material.” My guy friend is a sweet guy but I’m not attracted to him. I told him we’re just friends. We’re both tall, chubby but losing weight. He NEVER cared for the slim or hot girls. He only chases me.

Were both autistic. I’ve only had one boyfriend in my life (he has dyslexia) and he was a jackass.

I met other guys in the past but it didn’t go to far.

He’s NOT my boyfriend just to be clear.

Updates
10 mo
What if I end up meeting someone else? Then people with think I’m cheating on him. But my guy was just kidding.
Why did my dad ask my guy friend if he had a girlfriend? Why couldn’t he kept his mouth shut?
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