Lately our male pug has been peeing and trying to hump our female boston terrier.she rejects his action and they start fighting.they are both fixed and have slept together since puppies. They are now 3 yrs old.should we just separate them to separate beds?

It could be dominance, and separate beds could solve the issue. A lot of Altered dogs will still hump, and it is in fact a dominance thing. At 3 they are reaching their young adult lives, and maybe looking for a little independence from one another.