I have done spray tanning at a company called Beach Bum, it is a chemical that increases the melatonin inside your skin so after the chemical process happens it should not rub off. When you first get it it does have a surface color that you shower off about six hours later, that could rub off onto clothing. I went to the tanning salon in the evening, wore dark loose fitting clothing, got sprayed down by the technician, then you get air dried by a blower, then went on my way. I just hung out and tried not to sweat and went to bed and washed off the tanner in the morning and had a great looking tan that lasted about a week. You can pick what color you want, it was about $40 bucks, and if it's your first time at this company you can two for the price of one.
I would not put on self tanner then wear your wedding dress, you have to let the chemical work then wash off the tanner, then wear your dress. And, tell your fiance that tanning beds are dangerous, he should try the spray tanning if could save his life.