Eek! I wear purple tops a lot of the times because the colour suits me. Don't know what your sister thinks but purple is a great colour and funky. If people can wear red, white and yellow 's jeans what wrong with purple? You would look sexually frustrated if you wore tank tops or see through with short shorts, not because you've added a pop of colour :)
Lol no I'm not sure where she heard that but I've never heard of such a thing. I wear purple quite a bit and I'm not sexually frustrated nor has anyone said they thought I was. Purple skinnies sound hot imo.