Translation:We are painting inside, and they are sneezing outside.
I assume "meg" means "and". But so does "és". In what case do you use "meg", and in what case do you use "és"?
If they connect words / phrases, so when you are listing something, both can be used. If they connect clauses, meg expresses some kind of contrast, and I think it can only be used if the subjects of the clauses are different.
EDIT: Either the subjects or the direct objects have to be different.