Sometimes it takes a few months for the hormones to die down.
Also some dogs (male & female) just seem to enjoy it. A friend of mine has a female Yorkie 2yrs old that cries to get in her playpen everyday at the same time just to hump her toy. When she's finished she cries to get out. It's so funny. I have a female that has her favorite humptoy that will growl at any other dog that goes near it.
Don't know if this helped you or not.
Sorry to run on so.
