adding a puppy

Question
We bought a 1-year old chocolate lab (male - he's neutered now) from a breeder/kennel 4 months ago and feel that Java has made a great adjustment to our home. A week ago we bought a 3-month old yellow lab (female) from the same breeder. I know you said that labs love to chew on each other, but these dogs are crazy! The older dog will put his mouth all over the younger one - "mouthing" her ears, head, legs, etc. the younger one snaps like crazy at the older one. It all seems harmless even if a little rough. We try to keep an eye on them and break it up for a "time out" when it gets too rough. A stern "Ah, ah, ah, be nice!" has worked so far. My questions are - 1.How long will this go on? We haven't left them alone together because we don't want the little one to get hurt (accidently). When they calm down they are playing well together and cuddle up and nap together.   2. The older one is crate trained, but my husband doesn't want 2 crates in the house so for now we have the little one "penned" in at the end of a hallway with a gate - we were hoping to expand that area for both dogs. Do you think this will work?

Thanks for your help, I have learned a lot from you answers on this website already!

Answer
You can expect the rough play to go on for years, although it may slow down a little eventually.  it sounds like you aremanaging it as well as can be.  

One advantage of the crate is restricting activity extending the time a dog can go without eliminating.  Put 2 young labs in a crate or other restricted area, and they will continue their active playing.  I would look at one larger crate with a divider, or perhaps stacked crates.  I thought the one lady was joking when I read she had crates stacked 3 high in her living room.  She really does.  Crates can be tucked in unobtrusive places.  My daughter has one in a corner between the one wall and the sofa, and it sort of works like an end table.  

Another alternative would be tie downs.  They aren't quite as good as crates, but function much the same if you carefully keep everything out of reach.  Just a short length of chain secured at one end and a snap at the other.  They don't have to be obvious.  We have a couple of screw eyes on the underside of our kitchen cabinets in the toe area.  We can snap a double ended chain on one when ever we want to.