hmmmm… perhaps I am not understanding it correctly, but it sounds like you are inviting only 25 people to your wedding ceremony and reception, but then inviting another 45 or so to join you for dessert?
This is, as others have said, a tiered wedding. Where only certain guests “make the cut”. It is not socially acceptable, under any circumstances. If I were invited to “dessert” but was not included in the ceremony (aka…the wedding) or dinner, I would not consider attending if it involved ANY traveling. I would not drive or fly several hours to have some cake.
There IS a way to host a dessert only reception and have it be okay…but I was wondering what you meant by private ceremony? Like…only the two of you and the witness? Or only the 25?
Here are my two plan suggestions:
1. Have a private ceremony (just you two) and then celebrate another time.
Having a private ceremony followed by a non-private celebration always comes across a little odd for the guests. You want us to come celebrate with you? But you don’t want us to be there when it happens? So the best thing to do is seperate the two events. For example, have the ceremony the night before, several days before, or the weekend before. Then make this a weekend celebration with family and friends. You will want to also seperate the dessert party and dinner party, enough so that it is not obvious that only one group is invited to the other portion.
For example, wouldn’t you feel odd being invited to a birthday party at 2:00, and when you arrive they are having cake. But other guests were invited at noon and had a big lunch?
2. The (in my opinion) better option:
Invite everyone (all 25 + all 45) to a wedding ceremony, followed by a dessert reception. You can make this cute, while still inexpensive, but will need to be specific in the invitation. “Join us following for cake and champagne” so that people grab a snack beforehand. Have a designated start and end time (and choose times that are not meal times) for example 3:00 to 5:00. Once the party ends and most people have left, have some sort of break activity (games on the lawn? bonfire?) before having the dinner with the remaining guests.
Having the smaller group event AFTER will help avoid the sense of “oh, I wasn’t invited to that portion of the party” – instead it will feel like an entirely different event, for the guests who are staying at the venue.
If you are open to having a full reception, where all guests are included in the same hosted occasions, I would suggest this. It will help avoid hut feelings.