Translation:Your parents do not let you drink wine because you are a child.
Solution: "Seus pais não (o deixam)/(deixam-no) beber vinho porque você é uma criança."
I put this link in case someone starts wondering (like I did) about two direct objects (something they never teach us in Portuguese).
The explanation is that there is only one object, which is an entire sentence "você beber vinho", where "você" is replaced by "o", being "o" the subject of this sentence in the accusative form.
I knew I was right, but somehow I couldn't explain.....went down a grammatical hole.
It's indeed inconsistent....but we hardly notice this type of inconsistence. We understand "tu" and "você" as the same thing, even if conjugations are different.
In fact, many people conjugate verbs for "tu" as if it was "você" (it's wrong, but people are used to it)
In old times it could have been more evident, since "você" had a non-contracted form, used for special treatments.