My new dog tries to hump my old dog?

This is not a sexual thing at all. The puppy is trying to establish dominance over the older dog. It probably bothers you more than it bothers Quincy. My guess is that Quincy is just ignoring him and letting the puppy strut his stuff, picking his battles so to speak. When he gets tired of Charlie's antics, he'll put his paw down.

Since you need to establish yourself as the pack leader with Charlie, when you see him chasing Quincy or in the act so to speak, firmly tell him "No! Stop!" and give him your sternest look. Eventually, it will take just a look from you to stop him in his tracks. But allow Quincy an opportunity to put Charlie in his place. They do need to establish a pecking order. Charlie needs to learn that he is not top dog and he needs to learn that from Quincy.

We have four Cavaliers, a male and female who were our first two Cavaliers, a very senior girl we adopted from a rescue who is deaf and blind and just the sweetest thing, and our newest pup, another girl we adopted as a puppy a year ago. The newest little gal is very smart, very assertive, very much an alpha girl. She lives to try to put one over the other girl. She started doing things like taking Emma's spot on the bed (they each have their "spots", taking Em's toys, and just not being deferential to her alpha. Emma has responded by humping her from time to time and for the most part, we don't interfere, as Em needs top let her know her place. If it gets to be a bit much, I will tell Em "That's enough," but I will also tell Katie that she can't have Em's toy or move her out of Em's spot.

There's politics even with dogs LOL!

Charlie is trying to show Quincy that he's the dominant one and this can lead to more problem if you catch them say no and make sure Charlie gets off. Also if they aren't neutered it can help to get them fixed.

This is a dominance thing. Your younger dog is trying to show the older dog that he is more dominant. This is not a sexual thing. Just keep a leash on the pup and take him off the older dog whenever he tries to mount your older dog.

New dog is trying to be the alpha leader. Fixing him is probably the best way to stop the problem.

when charlie tries to hump quincy strongly say no. enforce it if you have to. eventually your dog will learn to leave your other dog alone.

Your older dog is expressing his dominance to the new dog. Correct him whenever he does this, especially if he does it to you. It isn't "love", it's a bad behavior.

he is just trying to show dominence. i do not think that they are actually..... when you have to males they need to find the dominant one and whoever is on top the bottom one usually gives a sign of submisive behavior and until then he will keep getting on his back.

I used to shout oi when my dogs were at it and that stopped them.

dominance.... he just trying to get a piece

You should fix your dog. If you want to breed there is nothing you can do.