sitting on our feet?

Apollo is leash reactive towards tiny/toy/teacup dogs (and small puppies). We've been working on it, and he's been doing great, I'm so proud of him. But, I have noticed that when I put him in a "sit" when a tiny dog is passing by if he backs up on my feet or is touching my legs or really any part of me his growl is a lot louder and deeper. If I don't let him touch me at all, just look at me, it's like the dog isn't even there, no growling at all.

I think Apollo touches me to "claim" me. But, I have no idea if your dog is doing that because she loves you or wants a pat or is claiming you or something else.

My opinion is there are many reasons dogs do it but that it is a very pushy behavior either way. 

 BlackLabbie, this reminds me of the way Penny will dare things with other dogs when I'm there that she wouldn't on her own. Unfortunately, being dependable back-up to your dog has disadvantages sometimes. If she's not confident about showing another dog a bit of agro, she will often do it from close to my legs, presumably because she feels more confident with me beside her?

Having said that, I think sitting on feet is generally pretty benign behaviour. Pen just loves being close to people. I get the "claiming" thing, but think of it more as a way for the dog to feel part of a group.