I think that the title of this peeve pretty much says it all, but if you need a visual to help explain what I am referring to, picture this: You're in a store such as Victoria's Secret (think underwear, bras, sleepwear, etc) when you over hear a couple talking about a lace-covered teddy or some similar concoction. Words like as sexy, "do you like it?", and such are coming from the couple. You're trying to find a properly supportive piece of functional underwear and would rather not be in the midst of their boudoir planning. But their giggling and suggestive shopping continues. Ga-ross.
Often times the man is actually viewing items as the woman tries them on, so you are not even safe in the dressing room, where he is hovering on the outskirts. Double gross.
Please buy your own undergarments or have that man buy your undergarments. Just don't go out and buy them together. And if you do, understand that everyone in the store is gagging on a rather large spoon.