Jennifer Garner would "do anything" for her husband Ben Affleck.

The Hollywood couple have been married for six years and have two daughters together, with another baby on the way.

Jennifer has discussed the secret to their happy union in a new interview. Both know how important each other's career is and Ben is also great at buying gifts for his spouse.

"We both know we couldn't do what we do without each other. Ben always says, 'If you love it, we can make it happen,'" she explained to InStyle magazine.

"He knows when to swoop in with the gesture. He's sweet that way. Honestly, I would do anything for that man, because I know it's not taken for granted."

One of Ben's "gestures" was treating Jennifer to two diamond rings, to represent each of their daughters.

The family are looking forward to the new arrival, although 39-year-old Jennifer admits this pregnancy has been tough. She's battled sickness and cravings, some of which have amazed Violet, six, and two-year-old Seraphina.

"My kids had never seen Doritos before. They would say, 'Mom, where did you get that orange chip? I really want that,'" Jennifer laughed.

"I wish I was one of those cute pregnant girls who wear skinny jeans throughout their pregnancies. But I just gain weight."