In marriage, many couples adopt a certain "what's mine is yours" philosophy. Sometimes it's just easier to sneak a little bit of your partner's favorite product from the medicine cabinet, after all. This mentality doesn't fly in all situations, but for Hailey Baldwin and Justin Bieber [1], there's at least one hair product the newlyweds both reach for.

"My husband, Justin, and I actually share the same Unite shampoo [2] in our shower," the 22-year-old told Marie Claire [3], revealing that most days she pairs the shampoo with her Mane 'n Tail leave-in conditioner.

"We definitely don't share skin care, though!" she continued. "I moisturize with a cream by Dr. Barbara Sturm [4] that's formulated with my blood, so I don't think he wants to put something that was made from my body on himself."

We all draw the line somewhere! Skin care may be off-limits, but since Baldwin is such a huge fan of her husband's scent [5], we do hope Bieber lets her steal his cologne every once in a while.