Красная веревочка или белая веревочка

I love bouncing on my exercise ball, feeling a g-string sliding along the crack of my ass. Then pullling th estring aside so my ass can breathe, imagining you fucking me hard on the wall as i wriggle my ass in ecstasy. But an mportant question, when you do this - should I start y wearing this red gsrring, or the tiny white on. You decide.