Formal invitation wording

"Together with their families..." I wouldn't want that many names on mine.

If they all contributed relatively equally, then “together with their families” with no individual names is appropriate. The wording you currently have, suggests the entire wedding was paid for by your sets of parents and that his maybe contributed a cake. (I just mean proportions)

I agree with “together with their families” as it is fairly wordy. His parents helped out a little with our wedding but we did not include them on the invite. Ours just says “you are cordially invited to celebrate...”

"Together with their families" is fine. However since we're paying for a majority of the wedding ourselves, we opted for "your presence is requested..."