Yep, not a problem! Males will almost always show sex before the female plants. And if you're not sure yet then that means you're not in any danger of the pollen sacs opening up, and you can keep him in there to get some good light. But when you see noticeable balls hanging from the stem, take him outta the room completely. A windowsill will be sufficient light for him to grow and open up the sacs. And I think they say auto's need about 30 days for the females to get a mature seed, so i would say rub it on the hairs of the girl you want to get pregnant around day 30 or so, and that should be plenty of time. Some ppl use a cue tip while i've heard others get better success with a small soft tip paint brush.
Of course all of your seeds will be regular instead of feminized, but you'll have sooo much you'll be set forever, or pass a few off to some friends!
My ratio has been about 3females to every 2 males.
BTW... pic of a finished bud on my blue him. Seems to turn a nice purplish bluish tint on the top of a nice lime green.