Unearthing The Magic Of Nelly And Tim Mcgraws Over And Over Feat Mcgraw By On Apple Music
Yes is okay to use informally and formally. It is incredibly informal and colloquial, and can be considered a form of slang.
I'm also a 36 year old dude, so maybe. I've never seen yus or yos, i've only seen yas. I'd call all three of those slang, only to be used very informally.
Tim McGraw & Nelly's Superb Collaboration for "Over and Over"
However, it is used most common online.
Story Behind the Song Nelly (Feat. Tim McGraw), 'Over and Over'
