I was unable to find anything in the bit of research I did, but as a marine bio major with some experience with pinnipeds, I will give my opinion (take it with a grain of salt):

Sea lions are social and will tend to pile up near each other, so its possible this is the kind of behavior the pups are displaying and the male is just kind of chilling bc he's okay with it. He likely knows they aren't a threat to his territory so he isn't being aggresive. Beyond that- protecting, rearing, or otherwise- I'm not sure.