Should I get involved when my kittens are playing?

I adopted 2 kittens from the animal shelter in our neighborhood. When we got them, they were about four-months-old and about the same size. The male has grown to be larger than the female and plays roughly with her. She spits and hisses at him, but he won't leave her alone. He's not trying to be mean to her, he only wants to play. Should I get involved and separate them? Both of the cats have been neutered.