Help!!!! How to disinvite guest? Is it rude?

[nieci]

Hi my name is nieci. Im getting married in DR next year. I decided to have my reception in a restaurant which only seats 70 people. I sent save the dates to a total of 85 considering some may not come. I also have a B list of family members who will want to come if invited. My issue is I dont mind single friends bringing a platonic friend of the same sex on the trip. Due to the fact that I would like to accomodate as many family members I would prefer if they decide to bring a platonic friend of the same sex that they do not attend wedding or just attend ceremony and coctail hour. Note: this guest will know other people at the wedding.

Is this rude? Please give me advice.