Normally, when the females bite back, I take that as a sign they're not ready. Most females will let the male give 'em the love bites and do their thing without fighting back when they're ready.
If the female still tries to bite the male I'd separate them for a couple days and try again.
I just left my males in with my females until I saw them mate (usually withing an hour) or overnight if they didn't look aggressive. I made the mistake of leaving a blizzard male with two females for a couple days and he was a little too...amourous... and got a good nip on the head because the females couldn't stand him.
But then some males are all around easy going and can be housed with a group of females all year round. My albino male was like that.
A couple lilttle nips aren't too bad, but if there's any blood/tearing of the skin definetly get them outta there. Some males or females are more aggressive than others, Use your best judgement.