Save the date......not followed up

[Jojo96]

We received a save the date for the wedding of a couple that myself and husband are both friends with.......the wedding is now 3 weeks away and we have not received an invitation of any form. Should I ask about it or just assume we are no longer invited? We seem them every couple of weeks and they haven't mentioned it...

Just text them 'hi, we've kept xxx date free as per your save the date - haven't heard anything else?' or something.

Yes, ask them. If they asked you to save the date then it's not rude at all to ask. If the invitation has got lost in the post they might think you're not replying!