The first time was in episode 6

The upset Yu Zhan'ao ran to the restaurant to eat a leg of lamb, and then blocked Jiu'er with a mask on his way back to his parents' home. He went to Jiu'er and carried her into the sorghum field. Having been suppressed by love for a long time, he wanted to possess Jiu'er. Jiu'er resisted with all his strength, but in the process of struggling, he gradually hugged Yu Zhan'ao...

Jiu'er The child she was carrying was naturally Yu Zhan'ao's, and she gave birth to twins.