senior female getting pregnant

Question
I have a 13 year old female lab. who hasn't been in heat for over 2 years.  we have 2 bern. mt. dog puppies. 1 year old male & female siblings. the male Will Not leave the senior lab alone, sniffing, licking, humping, panting. Is there any possibility of the lab getting pregnant? thank you for you help & time.

Answer
Chances are slim that she will become pregnant, however, a large young male dog like that trying to breed with her can hurt her in many different ways.

You need to keep him away from her and get him neutered so that he will stop doing this. Otherwise your other female will become pregnant and with siblings you don't want that either.

So get her spayed and him neutered as soon as possible. It's a bit too late to spay the lab.