Jessica Biel believes ''communication'' is the secret to her happy marriage.

The 36-year-old actress has been married to Justin Timberlake, with whom she has three-year-old son Silas, for five years now and is adamant the reason they're so strong is because they talk to one another about how they're feeling.

Asked her secret to a healthy relationship, Jessica told People magazine: ''Communication, communication, communication.

''The ability to be honest about how you're feeling and what your needs are. Just be able to communicate really honestly with your partner. That's worked for us so far. I would never want to speak on anyone else's relationship, but that's what we do.''

And the couple certainly aren't afraid to show off their strong relationship to the world and the 37-year-old singer recently shared a sweet photograph on Instagram of Jessica embracing him from behind along with the caption: ''She's got my back.''

The pair are currently focusing on their individual careers but have made no secret of the fact they'd like to add another little one to their brood - and hope it's a girl.

Justin said recently: ''I want to have as many kids as we can, if I'm being honest. I've never felt more inept my life. You wake up and all of a sudden there's this human being you're responsible for.''

However, Jessica may need a little more time to get over the trauma of giving birth to Silas as she was left in ''shock'' when she was rushed in for an emergency C-section.

She said recently: ''Our story with Nanny Connie started the day we brought our son home from the hospital. That may sound like a normal statement coming from new parents, except our birth plan was anything but normal. We had two midwives, one doula, one meditation birthing class, a ton of hippie baby books, and a lovely home in the Hollywood Hills that we had turned into a labor training facility that we called The Octagon. So, not exactly normal.

''When all our plans fell apart and the serene, natural childbirth we had envisioned ended with a transfer to the hospital and an emergency C-section, we arrived home exhausted, disillusioned, and totally in shock.

''I was obsessed with everything organic, toxin-free, natural, and homeopathic for our kid, who came into this world in an operating room through an incision. I was a dictator, making myself and my husband insane!''