Welcome to YT!
Congrats on your new addition!
We had a 50-60 lbs lab with our 6 lbs yorkie. Our first yorkie, though, was 4 lbs. Rusty, the lab, took some time at first to learn that Bandit was too small to be rough with. But after that, he learned to be very cautious and careful around smaller dogs. I think if you give your big guy time, he should learn. Just make sure to keep an eye on them, and seperate them if they get a little too rough while playing!