Translation:They are children of the same parents.
It isn't 'you have', it is just a weird inclusion of the genitive case for plural masculine. We saw it pop up in previous lessons in a different form... Ai mei (mine), Ai tai (yours), Ai lui (his), etc. Now we have 'ai acelorași' which is, I believe, the same construct. It just looks more complex since it's larger and less familiar.