Male kitten attacking female cat?

If your male is like mine, he's just playing. This will wear off with age. Mine is about 16 weeks now (not yet neutered). It is really hard to watch your older get cat getting distressed, but she'll eventually learn to batt the little one off and look after herself! My older cat is gradually learning, and I'm sure they'll be friends within the year! When my now older cat used was a kitty he was awful to my older boy (who sadly died in April), but they were best friends for years once he grew up. Good luck :-)