Every "Mad Men" fan is dying to know how Season 7 and the series will end. One person who is not an immediate member of the "Mad Men" family, on the other hand, already knows the show's ending.

In an interview with Us Weekly, Jon Hamm, who plays Don Draper on the hit AMC series, revealed that he has already spilled the beans about the highly anticipated series finale to his girlfriend, Jennifer Westfeldt ("Friends With Kids").

"Oh, she knows," he said at the CAA's School Day Benefiting Communities in School.

According to the 43 year old actor, there is nothing that he has not shared with his 44-year-old girlfriend.

"I tell her everything," he explained. "I tell her everything, and she definitely knows."

Hamm is confident, however, that Westfeldt, who he has been dating for 15 years, will keep "Mad Men's" secrets just that.

"She won't tell anyone," Hamm said.

Despite this indiscretion, Hamm said he has done a good job of keeping the finale to "Mad Men" quiet.

"I'm pretty good at keeping it secret by now," he said. "I'm looking forward to it. I think we'll have a good time."

Earlier this month, Hamm shared his views on the situation in Ferguson, Missouri, which is close to where the actor grew up.

"You want the facts to be presented in the most truthful way and I don't know what they are so it's impossible for me to comment on justice, or what that would be," he told British GQ. "What you hope for is that there is a truthful, honest, transparent process. ... Let's not assume things and make up things. It's really hard, it's a really, really hard situation."

The second half of "Mad Men's" seventh and final season begins on AMC in the spring of 2015.

---

 Follow Scharon Harding on Twitter: @ScharHar.