lingerie birthday

so my birthday is coming up March 7th I have been married for 5 years and I have never wear lingerie for my husband before I'm thinking about wanting to wear some for my birthday we will be going out to some sort of casino and getting a room and plus size I'm a size 18 with a big booty I don't know if I should wear some are not and if so where should I buy it help me please give me some advice