[MeadowCat]

I would personally tell them no. Puppies can certainly pick up bad habits (barking all the time) from other dogs. Plus, I would never expose my dog to a dog aggressive dog if I had the choice.

Our personal policy is no strange dogs allowed in our house. That means we can have playdates with dogs that are friends, but even those times I don't bring the other dog into our house. Both of my dogs are incredibly selective about the dogs they like. There are dogs that are friends that they wouldn't tolerate in the house. I also have to be really careful because we have cats.

 

[MeadowCat]

Is there a way you can say yes, with the understanding that it will be a crate situation pretty much exclusively? Maybe use some structured walks with them, without your boy, to "help" and bounce around some thoughts on training? Not in a "this dog is a terror" kinda way, but more of a "wow, he's so energetic and smart!. Let's see if we can teach him a few tricks (sit, heel, etc)"

I'm not a yappy dog fan, they are SO annoying. But then, so are in laws ;-) neither are going away, so make the best and try to guide the situation as best you can.

If you do say yes, I would absolutely do what monicaei suggests, with the added caution that I would NOT allow any interaction with Gunner, just to be safe.