Olivia Wilde wears her son's baby lotion to remind her of him.

Speaking to PEOPLE about motherhood, the mother of one said: “I love the smell of all the baby stuff. It’s all so lovely.

“[Otis has] been using [Mustela baby lotion] since he was tiny. And actually, when I go away for work and I can’t be with him for a couple of days, I bring a little tub of it and wear it.

“I don’t know if this sounds super creepy, but I wear it as moisturizer on my arms so I vaguely smell like him.

“People are probably like, ‘Why does this lady smell like diapers?’ ”

And, Olivia has revealed she feels her most beautiful whilst she is pregnant.

She said: “There’s something really beautiful about pregnancy.

“It is a time when you feel very connected to your body so right now — not having reached the point where I am definitely physically pregnant — I feel beautiful being in that space.

“And that’s kind of it, it feels great. This is what makes me feel best: when I can be in that space and be pregnant, but also be living my life and running around and working hard and being a good mom to my son and just feeling like, ‘Wow, I have all these internal and external factors that are making me feel great.’ ”

Meanwhile, the ‘Vinyl’ star’s son enjoys watching his mother apply her make-up, and has even tried to practice using cosmetic products on himself.

She explained: “Otis loves to watch me do my make-up and he likes to just sit there and stare at me doing it. The other day we were playing with his Magic Markers and he started doing his makeup with markers. And I was like, ‘That’s not bad! That’s an interesting shade you chose.’”