kittens and male cat?

Ok, well my cat gave birth to 4 kittens a while ago and now our male cat (who might be the father...not sure) has come along and seems rather curious about the kittens.

The mother and her kittens are in a box with blankets.etc and im not sure if its safe to let the male go into the box or go near the kittens? I let the cats lick each other than kinda put the male cat outside the room then he came in again and has been sitting outside the box moving closer every now and then.

So is it safe to let him near the kittens and go into the box if he wants?

Also do you maybe have any general info about kittens as its the 1st time we have had kittens.
To be honest I didnt even know our cat had had her kittens untill my mother checked her and noticed the kittens drinking

Thanks

Keep him away from the kittens and mother. If he's not neutered yet (which he SHOULD be), then he can breed with the mother and get her pregnant again while nursing kittens.

So if he's not done, take him in now and keep him inside and away from the mom cat for a good 30 days so he cannot get any other cats pregnant.

Then have her scheduled to be spayed when the kittens are about 8 weeks old or when the vet feels its safe to do her.

If he is neutered, it would not hurt to let him see the kittens, closely supervised. Many male cats love kittens, and bond with them like a daddy.
If he is not neutered, Goldenkitty was absolutely right. He should be kept from mom and babies.

Even if he is neutered, if its been done within that last 30 days or so, he STILL can breed her again and get her pregnant!