Wedding Invitations

So my fiance and are getting married in June. His friends are very lazy and after 5 years of knowing them, i have no tolerance to deal with their negligence. I have sent out invitations to all of them.
The invitation includes a response card, and a stamped envelope for them to return them to me. All they would have to do is mark which entree they wanted ,stick it in the envelope and then put it in their mail box outside their home. It is a common courtesy for the people i invited to send me back the reply card in the envelope when they are not going to come, so it would only be expected that someone who wanted to come fill out the card.

However, my fiance feels that if his friends "forget" or are to lazy to send it in before the reply date ( i sent them early so they would have over 2 months to reply), then they should be able to just tell me what they want, after i spent time and money printing out the invitations, envelopes, reply cards and paying for stamps to not only send them, but stamps so people could easily send them back