Complex sentence: He has a crush on Yun's girlfriend Houmei, but out of respect for them he doesn't say anything-also, Houmei's sister Shaomei has a crush on Yang himself.
Split into simpler sentences: He has a crush on Yun's girlfriend Houmei, but out of respect for them he doesn't say anything. Also, Houmei's sister Shaomei has a crush on Yang himself.