Probably making a little small talk with the other dad would get your kids some outside playtime like you seem to want.
I don’t really understand why you don’t allow him to play minecraft at home but do let him passively watch videos of it. Kids have special interests all the time – they throw themselves into things fully – I think you would get more out of trying to learn about his interest and engage with him about it.

They come by it honestly. I was the same way. I liked the idea of playing with new friends, but putting it into practice was always intimidating. It’s a work in progress. Thanks for reading!