The Lightning Dragon Slayer's Mate.
Although she didn't know it, Lucy had been sought after by Laxus. She was to be his mate. After he kidnapped her from the guild, the two disappeared for a week.
When they returned, the majority of the guild noticed marks on Lucy's shoulder, another on her neck. The marks looked like a lightning bolt. Just like the one on the left side of Laxus' face.
"Laxus, have you claimed Lucy." Mirajane, Fairy Tail's resident She-Demon asked. "Yes, I have. Lucy is now my mate. She is not to be touched by Natsu, Gray, or the other males." He says firmly. The members nod, heeding his orders.
Soon, Lucy discovered she was pregnant. Over the next few months, Lucy's bump grew in size. The other guild members simply assumed she was putting a lot of weight on.
She would often sit with Laxus, letting him run his hands over her steadily growing bump. Not that she didn't mind, of course. She found it rather sweet and endearing he was taking time to care for her and their unborn child.
The other guild members soon realised what she was carrying. Congratulating the soon to be parents, who were surprised to be showered with gifts. Caught completely by surprise, the mated pair weren't sure what to do.
Mira assured them to go on with life as usual. So they did. All too soon, the child came.
They named their twins Celeste and Fukuro Dreyar. Over the years, it got a lot easier to manage their twins rambunctious lifestyle. Since Wendy had claimed Romeo years before, it was surprising, the amount of Fairy Tail members choosing to settle down and make families of their own.
Cana x Bickslow, Natsu x Lisanna, Wendy x Romeo, Evergreen x Elfman, Erza x Jellal and Gray x Juvia. Along with Gajeel and Levy, the most unlikely pair ever to form. So it was no surprise when Sabertooth's twin dragons and their mates arrived to train and get stronger.
As Laxus and Lucy had disappeared for a year, taking their twins with them, everyone wondered where their favourite power couple had gone. A few weeks later, they discovered where Fairy Tail's resident power couple had gone to.
They were training for the Grand Magic Games.
After the games had finished, Lucy vanished for a day. Everyone had secrets, but Lucy's were the worst. Having lost her mother Layla when she was younger hit her hard.