Cute moment between these two
 
A backstory:  
Many years have passed since the defeat of the last major villain in Equestria (decades after the defeat of Tirek, Chrysalis and Cozy Glow) and Equestria is now enjoying another moment of peace, as Twilight now rules Equestria alone again, with Celestia and Luna, having helped Twilight to defeat the villain returning into retirement yet still returning to aid Twilight occasionally. The rest of the Mane 6, having ascended into alicorns, also aided Twilight in maintaining order and friendship. Luster Dawn had also followed her mentor’s hoofsteps being ascended into an alicorn and is now helping to govern Ponyville along with Twilight’s daughter Melody Aurora. At the same time, Melody, along with most of her friends, got married and all started having families.
 
In spite of the peace she enjoyed, Twilight felt lonely, seeing her subjects as well as her own children having families, and that she wished Flash Sentry (who died on the day Melody was born attempting to protect his family) was still alive and they would have added another sibling or two for Orion and Melody. One night, as Twilight lay weeping in her bed, Flash’s spirit came, and Twilight told him about his problems. After hearing her troubles, Flash agreed to do it with Twilight, though Twilight was concerned, as she is already a ruling princess and that Flash is dead and that it may be unnatural to have children again. Flash assured her that everything will be alright, as the ruler of the afterlife had granted him a special status, given how his family had achieved many hardships. Despite still having doubts that she could bear children from a ghost, Twilight decided to have her fun with her hubby anyway the next night. Soon Twilight began experiencing symptoms and she soon found herself to be pregnant, much to the surprise of the Mane 6, her son and everypony else. Twilight was delighted and surprised at the same time, as Flash really proved her right. A few weeks later, Twilight found her belly swelling fast. Fearing that her pregnancy was a rapid one, she went for a check, and another surprise came: she was carrying 20 babies! Twilight then began feeling uncertain, as this was her first pregnancy in over 30 years, and she was carrying that many in an instant. Then, she got word that Cadance, Flurry Heart, Flurry’s youngest octuplets daughter (who’s 14), Orion’s wife, Melody and many more of her friends were all pregnant with differing amount of kids, with Cadance having the same amount of children as Twilight, Flurry having duodecaplets and Flurry’s daughter carrying nonuplets (all while having an affair with somepony from a land far away). After learning that Twilight wasn’t the only one pregnant with a large number of babies, she became determined to bring them to full term, with the support of her pregnant and non-pregnant friends and relatives, as well as Flash, who she and him were eager to see how their children would carry ghost traits.