My male guppies chase my female mollies quite a bit (in fact they seem to ignore the female guppies in preference to mollies) Will they crossbreed? I suspect no but after seeing this behavior consistently I am starting to wonder.
It is possible. Platies and swordtails can crossbreed and guppies and mollies can crossbreed. It is much less likely if you have some female guppies, it's more likely if you only have male guppies and female mollies or only male mollies and female guppies
Cool, hope it happens could be interesting looking. I suspect one of the mollies is pregnant again, wonder if that influences the guppies to chase her? However they do chase both females they favor the one that looks pregnant. Never thought I would be paying so much attention to fish courtship LOL.