Is this a prank?

"This is a prank, right? How can my sister be pregnant?" Lanni was in disbelief. It was impossible no matter how she thought about it. Luna wasn't even close to any… 

Her train of thought paused when she realized what Xiehan had just said to Jiang Xingyu. Congratulations?! 

Did that mean Jiang Xingyu was the father of the child? 

Now, that was more shocking. 

"Does she know?" She asked. 

The doctor, who was waiting for them to calm down before telling them what to do or not to do, shook his head. "The nurse will tell her about it once she wakes up." 

Lanni shook her head and let out sigh after sigh. 

Xiehan laughed at her expression of disbelief. "You still don't believe it?" 

She shrugged. "Well, you can always trust Luna to remain calm for ages and then unleash one brilliant feat when no one expects it." 

The man laughed, then turned to his friend who seemed to be uneasy. "What is it? Aren't you overjoyed?"