He first revealed, "Nowadays people call me 'nation's father-in-law' because of my kids. My oldest daughter is actress Gong Seung Yeon and my youngest daughter is TWICE's Jungyeon. I can't help but smile when I look at the two." 

SEE ALSO: Nature member Haru addresses the promotional video introducing her as a hostess at a Japanese adult establishment

Yoo Chang Joon continued, "If my youngest one Jungyeon brought home a boyfriend, I don't think I could take it." 

Uh-oh, Jungyeon's boyfriend better watch out for Papa Yoo!