Keep an eye on it. How are your water parameters? Do the edges fall off or look like they are falling off? Or getting shorter? Most of the males I have that get white tips, the white tips is growth from previous damage such as fin rot or tail biting.
I wouldn't worry too much, just keep an eye on him, If he starts to get lethargic then maybe try him on treatment for fin rot, as far as I can see he's just growing his fins out for the ladies usually fin rot makes the end of the fins go either black (like they're burned) or red (like they're bleeding)