I am a 34DD and I got a M/L and it fits like a dream. I was a little disappointed that the thong is apart of the garter belt as I was hoping to wear it with different panties at times but that's alright I guess especially for the price. The thong par is a little loose which is surprising but not necessarily a bad thing as this number will not be easy to take off. All in all I'm happy and I'm sure he will be too