Male platy picking on female platy.

[Guppy Mad]

I have got 2 female platies and 1 male platy and bought another female platy today.
But the male platy likes the other 2 females but not the new female hes keeps trying to bite her do you know why?
Could it be that i bough a swordtail but i didnt think it would be please help.
Thanks...

 

[MountGuppy]

it might be a swordtail or it might be that they just dont like him