What do I do about my girl cousin ?

Is it bad that I notice that my girl cousin has big boobs and a big ass or is it her fault becasue she wears clothes that are really tight on her and they really show of her body like her cleavage she shows off her boobs like no big deal she pretty much wears her shirts as low a possible to wear you can not help but look at her boobs when she walks in or when you talk to her one on one and her jeans are so tight I don’t see how she get’s them on. And is it wrong that a get a boner when looking at her and before you say yes it’s wrong it’s your cousin I would never do aney thing sexual with her so don’t waste your time