Being without his alpha was torture for Derek, but deep down he always found ways to have fun, like showing his milk-filled breasts to other young alphas.
Stiles still remembers the time in his youth when his father kept him caged to prevent him from impregnating other bitches, although despite all that he managed to impregnate the alpha Hale without being able to stop it
You can't expect much from a chained whore, but Derek was still everyone's favorite. Learning to be a prostitute was quite a job, and having an ass willing to take so many cocks was his talent.
Many men in town didn't know why Stiles was chosen to be the alpha Hale's mate, what he had that they didn't; well, that was something only Derek could know.