People.com Entertainment TV 'Extreme Sisters' : Lucy and Anna See Doctor About Having Kids at the Same Time with Shared Boyfriend In PEOPLE’s exclusive sneak peek at Extreme Sisters, Lucy and Anna see a fertility specialist about having children at the same time By Ally Mauch Published on May 14, 2021 10:52 AM Share Tweet Pin Email Extreme Sisters stars Lucy and Anna have an unconventional request for their doctor. In PEOPLE's exclusive sneak peek at Sunday's episode of the new TLC series, Anna and Lucy DeCinque, 35, seek out a fertility specialist to ask some questions about starting a family. Like everything in their lives though, the pair want to do it together. "We're thinking we want to start a family so we want to know our options," Anna begins. "And you have partners?" the doctor asks as they reply in unison: "We share a partner." "We have one boyfriend that we share together, his name is Ben," Anna says. "And we see us having a child with him, both of us," adds Lucy, while Anna explains further, "Not just one child, two babies. She needs to be pregnant and I need to be pregnant at exactly the same time." TLC Extreme Sisters' Anna and Lucy Want to Start Family with Boyfriend: 'We Have to Be Identical' At this revelation, the doctor appears visibly uncomfortable. "In my life I haven't seen anyone sharing the same partner and wanting to get pregnant at the same time," he tells the cameras. "So yeah, I was a bit shocked to listen to what they were aiming for and what they came to see me today for." "I have to say it's not a usual scenario I'm facing but as doctor's we are ready to discuss different things with my patients," he adds. Lucy and Anna then have some more specific questions about the mechanics of both of them getting pregnant via Ben at the same time. "Can I ask does he like need to [bleeped] with me and then 10 minutes after like straightaway with Anna? Is that possible?" Lucy asks. Anna continues, "Please forgive me, if we gave him like a [bleeped] and we quickly did the turkey baster and quickly in her and then me, is that possible?" Anna and Lucy with boyfriend Ben. TLC Extreme Sisters: 2 Adult Siblings Continue to Sleep in the Same Bed in New TLC Series After a pause, the doctor replies, "I suppose yes." "They probably noticed I felt very uncomfortable when they went into those details with me," he tells the cameras. "But they are here for my advice and I give them my advice. When they ask me questions, I give the answer." He then explains to the pair of sisters, "So generally, women over 35 years old, the chance of getting pregnant every month is about 15 to 25 percent, but let's say look you want it to happen at the same time, 15 percent is 1 in 6, so two at the same time is a 1 in 36 chance that you can get pregnant naturally at the same time in the same month. "That's not good enough for us," they say in unison. Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories. To the cameras, Lucy and Anna share that the experience at the doctors was upsetting for them both. "To be honest everything he said was a surprise," Lucy says, before asking her sister, "Did it piss you off? Did it affect you, like did you want to cry? "I kind of stopped myself, it really upset me," Anna says. Extreme Sisters airs Sundays at 10pm ET/PT on TLC.