A question about my dog?

Okay, so I have a male Labrador Retriever and he is about 12 years old. He never got fixed. Many of my friends came over before and he didn't do anything (all female friends). However, when my one friend (female) comes over, my dog like gets really horny. Today when she came over, he was trying to hump a pillow. He hasn't tried to hump anything in like over 5 years. She has a female dog, which he might have smelled, but so do my other friends. The friend that he gets horny around is kinda a slutty person. She has already been pregnant. She is my only friend that was pregnant already. Does this have anything to do with it? Why does he act this way around her? Please help, this is a serious question.

[margypops]

Your dog does this because he hasnt been fixed and he still, although older has the urge to mate with another girl dog, I am not a vet but he is pretty old to fix now. Maybe the answer lies in keeping him away from your firiends put him in another room when they are at your house. Maybe your friends think it funny and the behavior is encouraged? Ask your parents to keep him away when the Friends are around.

[margypops]

We also have a forum for dog questions you may get some further input there.

[teko]

It is my understanding that a dog cn pick up on a womans scent. Especially during or right before her period. I always wondered why this happend and read it on a site about animals.