Sean, 33, admitted he has a hunch Catherine, 31, is pregnant with another boy, but he'd apparently love his wife to bring her mini-me into the world.
"Samuel has blond hair and blue eyes and a lighter skin tone and he looks like me, so I'm hoping if it's a girl that she'll look like Catherine," Sean said. "I would love a little brown-haired girl."
Catherine and Sean, who said they'll be "so happy either way," have no intention of finding out their baby's gender before his or her birth.
"We're not going to find out the gender," Sean revealed. "We didn't with Samuel, and it's really exciting to be in the hospital and find out. And neither of us are Type A planners, so we're fine with it."
But what's most important to the couple is that they simply expand their family and raise healthy children.
"Catherine wants five kids," Sean noted to People. "And we want to adopt as well. It's all a learning process!"
The pair acknowledged Samuel doesn't understand what's happening right now, but at the same time, he's very bright.
"Samuel still has no idea what's going on, but it'll be fun because he advances so much," Sean explained. "He doesn't grasp the idea yet, but we're pointing to Catherine's stomach and saying 'baby.'"
As for how Catherine's feeling during her second pregnancy, she's very lucky.
"I'm more tired [this time around], but I've never been nauseous or sick, even with Samuel," Catherine gushed to the magazine. "That makes me think I'm either made for this or it's another boy! I feel really blessed to be feeling so good."
Sean and Catherine got engaged on The Bachelor's finale in 2013. After Sean competed on Season 16 of Dancing with the Stars that year, the couple tied the knot in a live ABC television special that aired in January 2014.
They both subsequently appeared on Celebrity Wife Swap and Marriage Boot Camp before Samuel was born last year.