My wife and I had Golden Retrievers growing up, and we owned a Golden and a Chocolate Lab shortly after we were married. I think we filled the roles of pack leader, playmates, and cuddlers all at once, as we had no kids at the time.
Now we have three boys, and it is interesting to see how our 6 month old yellow lab (Nigel) interacts with us. My boys are clearly his fellow playmates, but even with them their are different dynamics. While Nigel is a submissive little guy, he gets jealous when our youngest is in the bed with us. He's a *tad* dominant and a little protective of him, too. We're actually amazed at how patient Nigel is with him. The older boys seem to be his favored chums.
Interestingly, Nigel does not initiate much play with my wife and I, although he tries to crawl into my wife's lap whenever she sits on the coach. She seems to be the designated cuddler. And while he'll play and cuddle with me, it's (again) rarely initiated by him. On the other hand, he tends to stay by me, comes to me when he needs to go out, and will not typically go to bed until I do. At first, I was jealous that I wasn't his first choice as a playmate and cuddler. On the other hand, he behaves well, respects me (most of the time), and seems to hold me in high regard. Pretty cool! It occurred to me that being a pack leader and a playmate are often discrete roles.
I'm wondering if your lab-experiences are similar? It's interesting to see the complex social dynamics and bondings at work here. Dogs are remarkable creatures!
Apologies for the typos! Looks like I'm not able to edit after two-minutes of the initial posting.