I guess a lonely frustrated platy might try, but they cannot cross breed. They are not of the same genus. As far as I know all of the Xiphophorus species can cross breed which are various platies and swordtails. I cant remember the guppy genus name, but it includes guppies and mollies and they can cross breed. The two genus are closely related and as a result very similar but they can all only cross-breed within their own genus.