Happy Holidays and Merry Christmas to all! I haven't been around for a while (insane family stuff) but I have a question to which I haven't been able to figure out the answer.

Our lab mix, Loki is usually very relaxed. He's our alert watchdog but is usually pretty unfazed by most things. However, we just purchased a body bag for my kickboxing propensity. It's a floor model (the type where you fill the base with sand or water) and it's down in our utility room.

My husband and I were trying it out for the first time a few nights ago and Loki was watching. I initally started out doing some kicks and punch combinations. Then my husband tried a few. As soon as hubby (Frank) started punching Loki became agitated. His ears laid back, and he crouched slightly but his tail was still wagging. Then he darted over to Frank and watching him punching for a second or two and then nipped him on the bottom! He was immediately corrected by me and put in a down-stay and he was fine. He watched Frank but made no attempt to break and did not appear agitated.

I let him up after about a minute and he immediately darted towards Frank again and tried to nip his thigh! He did not appear aggressive per-say but I can't figure out why he would behave like this. The only difference between Frank punching the bag and me punching it was that Frank was wearing gloves so we tried to see how Loki would react without the gloves and it was the same.

I realize we can just crate him if need be but I'd like to understand the behavior if at all possible.

Anyone have any ideas what might cause this?

Is it a play behavior? Maybe he thinks he's missing out on all the fun. I know that if I play fight or wrestle around my pup he gets all worked up.

Yeah, we thought about that but when we (Frank and I) wrestle the dogs are pretty calm. They usually just watch. We also don't really wrestle with the dogs. When we do play-fight or wrestle with them they are NOT allowed to mouth or use their teeth in any way.

Could be play.
But when my GSD's ears go back it's because he is mad or nervous. His tail still wags, just like the OP's lab mix, but my dog is still assessing the situation. He may take a few minutes to decide on the situation. He either perks up (he gets comfortable with the situation and his ears return) or his tail stops wagging (he decides he doesn't like it).

However, you know your dog best. Maybe your dog is correcting your husband for being too aggressive. As the leader, maybe you are the only one that's allowed to be aggressive.

Consider the source (me) and do what you want with my thoughts. :-)