Mercede Johnston, sister of Levi Johnston and aunt of his baby, Tripp, with Bristol Palin, will be appearing nude in the September issue of Playboy. The 18-year-old has also taken the opportunity to continue her ongoing feud with her almost sister-in-law.

Mercede has a blog where she has tells her version of her brother’s relationship with Bristol, and there seems to be quite a bit of acrimony between the two, particularly over Bristol’s memoir, “Not Afraid of Life: My Journey So Far.” Mercede said last month it should have been named “Not Afraid of Lies.”

Now she says Bristol sent a text message to Levi after she found out she was pregnant that said: “Ever since the moment I found out I was pregnant, I prayed to God you weren’t the father.” Oh, dear! That sounds like she was hoping someone else was. These are the reasons parents warn their children to be careful what they put in writing, not to mention not to be telling their friends all their business, because this is what can happen when the friendship goes south.

Mercede also took a few pot shots at Sarah Palin, when asked what kind of President the former Alaskan Governor would make. “I think she’d have had a mental breakdown …. As governor she quit on us. What does that say about her?” She also believes that 70% of Wasilla residents “can’t stand Palin.”

The other 30% apparently affect her ability to work. Mercede claims: “It’s hard to get a job in this town because of the Palins,” she told Playboy, “People say, ‘Oh, Mercede Johnston, I don’t know if people are going to come in if she works here.'”