Two babies, each one born to a different partner, both using the same sperm donor. Are they twins if they don’t come from the same womb? Are they siblings if they are born so close together? What do people call two children born to a couple under such a special circumstance? Twinblings.

Celebrity makeup artist Toby Fleischman and her partner, speech pathologist Lindsay Lanciault are each expecting a bundle of joy this summer, due just three weeks apart. The couple announced the news on Fleishcman’s Instagram to her 12,500 followers and were met with love and support. The two have been married almost three years, and are welcoming their first human babies, who will share a furbaby sister.

Both babies share a sperm donor. Fleischman is due first, currently five months along, and Lanciault will follow along shortly, currently four months along. Fleischman, who is 41, tried to get pregnant first since she was older. She tried for over a year, during which time she suffered a miscarriage. After much discussion, Lanciault then also tried to get pregnant. As luck would have it, both found out they were pregnant in late 2016, and it has had its ups and downs.

“If she’s [Lanciault] feeling something that I’ve gone through, I can validate it and say that that’s normal,” Fleischman told Popsugar.

“But there are a lot of hormones in the house and we go through waves in one day of being obsessed and in love with each other and so euphoric, to ‘I don’t want to be next to you. Please don’t talk to me.’”