Translation:Tonight we must eat at our parents' house.
I put in "We must eat at our parents' tonight" and got a "nearly!" because apparently it shouldn't have an apostrophe - pretty sure it should have one there. (Not complaining because it let me pass, but the apostrophe should be there surely because the "house" following it is implicit in that phrase?)
'With' indicates that you eat in your parents' company but not necessarily at their house. You could also go to a restaurant with them. This would be 'met' in Dutch. I think 'bij onze ouders' means that you are going to be at their house, like 'bei' in German or 'chez' in French, and 'with' doesn't convey that.
Welcome to Duolingo. The owl can't handle s apostrophe, though he is generally ok with apostrophe s. Interesting debate in others' comments, though, about which preposition to use. It occurred to me that a change in preposition would require a change in punctuation:
We must eat with our parents tonight.
We must eat at our parents' tonight.
While technically not incorrect, "We must eat at our parents' home tonight" sounds awkward. "House" is definitely the more commonly used and natural-sounding term, at least in the States.
It's nice to know all translations, but I do think there's more value in learning to speak the way a native speaker would.