My fiance and I live together and it's destination so it's not too formal But The addressing to people i am doing correctly with "Mr. and Mrs. (Male name) (Last Name)". And we have a couple of guests who are engaged so we are addressing it "The Future Mr. and Mrs. (Last Name)". Would it be okay to address the return address the same way... "The Future Mr. and Mrs. (His Last Name" with our address following it?