Invite Question

I have an outside envelope and an inside envelope. I was going to put on the outside
Mr. John Smith

And on the inside

John and Guest

Is that correct or can I just write on the outside envelope

Mr. John Smith and Guest

and leave the inside envelope blank?
Im afraid that they wont see the inside writing and think I invited them without a guest.

I need help

I think the correct way is:

Outside Envelope:

Mr. John Smith
Address
City, State Zip


Inside Envelope:

Mr. John Smith & Guest

or

Miss Jane Jones & Escort

Unless you know a couple is together, then:

Mr. John Smith & Miss Jane Jones


Hope this helps you!