What says sexy time to me? Lace bras, specifically ones like this Miu Miu Silk Triangle Bra ($320). The fact that it doesn't have an underwire makes it so delicate, and the combination of lace and satin is quite delectable. I would totally wear it to bed and out as a visi-bra. Too bad it's so darn pricey.
To see the look for less,
How darling is this Aerie Chiffon Trim Bralette ($20)? It exudes romanticism like the Miu Miu bra, only it has different colors and a totally different price tag. I love the mix of sapphire and black, but it also comes in pink and black, or ivory and black.