There is a young lady at one of my jobs who always wears yoga pants to work. She's got the body for them, but I think its a risk. Several months ago, there was a creepy customer who, after making his purchases, just stood in back of her while she checked out other customers and stared at her rear end. The guys she was ringing up after Mr. Creepy noticed him staring at her and confronted Mr. Creepy, which I thought was rather gallant of them. Shouting ensued and threats of "taking it outside" and such.
I think Mr. Creepy was scared away, which is a good thing. If he hadn't been, I would have suggested that someone escort her to the parking lot when she left work.
Now, this might have happened even if she had worn more loose fitting pants because she is an attractive girl, but you've got to wonder. I think that if I was cute and young and had a good figure, I would probably not feel comfortable exchanging yoga pants for my jeans.