What's "fake" about 2 gay couples — where gay marriage is illegal — colluding to create 2 opposite-sex couples?

Here's this Daily Beast article titled "China’s Fake Gay Marriages":

In China, where homosexuality was classified as a mental illness until 2001 and a crime until 1997, gays and lesbians still face serious discrimination, [and] where the pressure to get married is strong and starts early, it has long been common for gays to marry straight spouses. Now, some are finding what they consider a better alternative. Known as “cooperative marriages,” or hunzuo hunyin, gay men and lesbian women are increasingly marrying each other — often aided by the Internet. (Such marriages are also known as “fake marriage” [jia jiehun] or “ritual marriage” [xingshi hunyin].)

This could be a structure for producing children — children who could then live with both biological parents. Obviously, a male and female can produce a child together, without ever having sex and without medical intervention. In China, this is being done in a way that deceives their family, and sometimes they're doing nothing together but having a wedding. So, depending on what the couple does, it could be fake. But what if, say, a female gay couple and a male gay couple were compatible friends, who pooled their resources to buy a big house and they really wanted to raise their children together responsibly and with both parents in the house. Would it be wrong for the males to marry the females?