That's quacktastic! The Duck Dynasty family just grew by one. Willie and Korie Robertson's oldest son John Luke Robertson proposed to his girlfriend Mary Kate McEacharn on his 19th birthday, the family's rep confirms to Us Weekly. 

"I am so excited to marry my best friend," John Luke tells Us. "I know my parents married young as well, and they have always been examples of what 'could be' to me.  Fast-forward 22 years and they are more in love than ever, and I hope Mary Kate and I are the same way in the years to come. God has truly blessed us."

The reality star popped the question before the couple posed together in several sweet Instagram photos. McEacharn posted one on her account flashing her new bling as her fiance held up the sign reading "Future Mrs. Robertson" with an arrow pointing to her. 

Rebecca Robertson, Willie and Korie's oldest daughter, also posted a picture with the newly engaged couple, captioning the image, "She said YES @missmarymcmcmc so excited to be your sister." 

Dancing With the Stars contestant Sadie Robertson came home to celebrate her brother's birthday and be there for the big moment. 

John Luke has appeared on 29 episodes of the hit A&E reality show with his family. He is also a juvenile fiction writer, penning the book Willie's Redneck Time Machine Be Your Own Duck Commander.