"Yijian nigu, fengdu bishu!" Once a nun is sighted, all bets shall be lost!
So joked Ling Huchong with Tian Boguang, in an attempt to get him to free Yilin. When Dingyi heard about this, she was furious, but Liu Zhenfeng calmed her down by telling her it was all a trick, and asking her "If we male disciples of the 5 Sword Alliance truly believed this, how could I have asked you (nuns) here on this occasion, for my Gold Basin Hand-washing ceremony?"
Ironically, him and his entire family/students were killed at that ceremony!
Actually, in the rest of the book as well, whenever the nuns show up, Ling Huchong seems to get screwed over. I mean, after seeing Yilin, he almost dies from sword/knife wounds from both Tian Boguang as well as the Qingcheng disciples. After a while, he manages to not see her a while (due to being in isolation on the mountain). He even has a run of good luck, learning Dugu Jiujian. Then what happens? The 6 Freaks of the Peach Valley ("sent by Yilin") come and ruin his martial arts! After Yilin herself shows up with her dad, Ling Huchong is suspected of learning Pixie Jianfa by Yue Buqun and others. After a long period of time without seeing any nuns, he finally gets another run of good luck; having Ying Ying fall in love with him, being offered Yi Jin Jing by Shaolin (although he turned it down), learning Xixing Dafa and getting healed...then all of a sudden, he remeets Dingyi and later is forced to become Headmaster of the Hengshan nuns, and stuff starts going downhill -again-!
It looks like nuns really -are- bad luck! Poor Liu Zhenfeng!