You receive an invitation, it has an RSVP; a date to do it by & contact information.
You don't bother RSVP-ing.
AIBU to think this is very bladdy rude? I am the inviter, I have 40 invitees, I have received 4 replies.
Why don't people bother RSVP-ing? Anybody know? Rude arseholes? Very busy lives? Suddenly can't read? Hand fell off so can't text?
If I was in a worse mood I would possibly say DONT COME TO MY EVENT THEN YOU PRICKS. I WILL DRINK ALL THE WINE AND EAT ALL THE CAKE MYSELF.
Honestly though, you receive a personalised invitation to a day that is special to your friend and clearly costing money and needing organisation and you just don't bother getting in touch? Terrible form.