Forever with the Flash (Barry Allen, The Flash)

Sequel to "The Time of Flash"
It's been a few years since Serenity and Barry Allen confronted Savitar and other villains with still being great parents to their six year old twins, Dawn and DJ Allen. They've met other heroes and joined teams with them while still being their own team with Cisco, Caitlin, Iris, Wally, and Joe. Their twins are now nosy in what their parents do and question the past. Serenity and Barry will have to revisit a past that almost tore their family apart.

What happened in the past? How do they do being parents to twin speedsters?