Plus-size gals like to look pretty just like everyone else; even in the bedroom. On the sites listed below you will find lingerie that is in good taste and lingerie that is more risque'. Check out these sites. I hope you can find what you are looking for.
Hips&Curves "Your Ultimate Plus Size Lingerie Boutique" Here you will find a large variety of items, including but not limited to garter belts, peignoir sets, corsets, costumes, and sleepwear.
Lane Bryant-Cacique On this site you will find new arrivals, bras, panties, seriously sexy lingerie, sleep & lounge, and shapewear.
macy's If you are looking for hosiery, shapewear, gown & robes, or bridal lingerie you may want to check out what macy's offers.
Torrid This is a plus-size site that has a selection of intimates. Some of the categories are bra and panty sets, bridal, shapewear, and sexy lingerie.
I'm sure you will be able to find some intimates at other major department stores. The online sites I have listed above have a decent amount of items. I was very surprised to find that there are just a few companies offering pretty things for us larger girls. If you know other sites please feel free to include them in the comments section and I will add them to this very short list.