I want to know if she is in heat due to her humping and cleaning our male ears and very affectionate.

Dogs will clean other dogs' ears. It's just what they do. But you should try your hardest to have her stop licking his ears... her saliva inside of his ear created ear infections.. and actually, you should look into getting his ears checked for an ear infection.

What kind of "Stuff" is coming out of her nipples? Is it white? Is it clear? Dogs typically begin to milk a few days before they have their pups. But they can start to milk if they went through a phantom pregnancy. Those typically appear after a heat cycle.

She isn't humping the other dog due to sexual frustration. Humping of the opposite sex could mean two things, dominance or under-socialized.

How is she becoming "very affectionate"? Is it because she is cleaning his ears? Pack animals are affectionate to one another.

I would recommend you get her spayed. It sounds like you are not sure what to look for in a heat cycle. Spaying your pet has more benefits than it does cons. One, you won't have to watch her and your male 24/7 to prevent breeding, two you are helping decrease the number of unwanted dogs and three, you are helping her avoid serious health issues females have such as pyometra (infection of the uterus) and breast cancer (Yes, dogs can get breast cancer).