"Odd" grooming behavior; tipping nose?

I work at a local trail riding/lesson "joint" with twenty-four head in the herd. Of them, I will ritually groom at least six (while other workers help doing the rest). Creampuff and Ben are in this "group" that I groom.

I've noticed that they do something none of the other horses do while I'm grooming them. While I'm at their side (usually after I pass their girth line) they will tip their noses toward me, looking at me straight on, and stare for about ten seconds before looking forward again. They do this on both sides while I groom, and will do the same when I bring the tack.

Does anyone know what this behavior could mean? It's not aggressive or dominant (they don't nudge, push, pin their ears, or try to bite), but none of the other horses (even the severely passive ones) exhibit it.

I'm simply curious; it's not a dramatic, concerning behavior but it is rather strange to me.

Perhaps they are just curious about what you're doing?
I'm not sure if it means anything

A friend of mine asked that, and I said that it sounds strange to be curiosity because I use the same routine (same order or brushes and such) regularly. At first I thought nothing of it (like you said, maybe it means nothing), but it soon started to happen each time.

They aren't invading my space; they don't snap, pin their ears, or any of that. They simply look. Sometimes they'll prod my arm with their upper lip. It's also strange to me that I use the very same routine with the other horses (including our youngsters), none of them do this.

Maybe they both happen to have tickley spots there? I know horses have special spots for mutual grooming, maybe they have an unusual spot where they get that reaction?

I've actually had horses "grooming" (usually wiggling their top lip while nudging) walls, leadropes, haybales me in response to hitting one of their "spots" Its rather silly and fun to watch, and the horse enjoys it too.

I never thought of that, Masatisan. Thank you! Creampuff has a "scratchy spot" on her chest, and Ben's I haven't found for sure just yet. His is a wanderer. Haha. I was mostly curious as to what it would be. Should it be a behavior I should correct? They aren't being pushy or "mean," so I would think not.

Thinking about the horses having "ticklish" spots is a humorous idea. Knowing that it's a mutual thing of affection and respect, I enjoy doing it with the horses. Our filly, Little Bit, has a good spot on her neck; she'll tip her nose toward the sky, tilt her head, and jut out her upper lip. So adorable!

Willie does the same thing.
He generally enjoys being groomed as well. I would say if the horse isn't being pushy, rude, or invading your space in anyway there's no reason to "correct" the behaviour because they aren't exactly doing anything wrong.

Regena does the same thing. She'll often turn her head towards me while I'm grooming her. Sometimes she just stares, sometimes she sniffs at my pockets and sometimes she tries to take the brush. Maybe she wants to groom herself I dunno.

It sounds like they are just enjoying being brushed and interacted with to me :) As long as the behavior doesn't turn negative I don't see it as needing to be corrected. I know horses that will lean back on there front legs when you get their itchy spot, and rock back and forth with their lip out towards the sky until you stop lol.

They are "mutually grooming" . Horses will stand end to end with each other so they can mutually groom those extra special itchy spots, usually right behind or at the shoulder/wither. As long as a horse continues to groom the other, that means he still wants to be groomed. If he stops making lip movements and kind of stretching his head out and cocking it to the side, then he us indicating that he's had enough. Some horses take it a bit too far and try to "groom" the human, and this is with their hard teeth, but most horses are polite enough to just ritually groom with their lips.
I love it when they do it. I say, "I found your sweet spot!"

If they do this consistently they're probably a little girthy. Or they could just have thin skin and a little more sensitive in those areas.