If you attend the mainstream LDS church and you go to Gospel Doctrine for Sunday School, then you're probably in Alma right now, close to the Corianton chapters. If you have no idea what I'm talking about, you can read Alma chapters 39 through 42 online or just keep reading for a brief overview.
In chapter 39, Alma lays out some serious allegations against his son, Corianton. Alma says that Corianton fled his missionary work with a harlot named Isabel and... *gasp* had sex with her. Alma goes on to explain that sexual sin is the worst kind of sin (okay, unless you're killing or denying the Holy Ghost), then he goes into a huge lesson on the resurrection and plan of salvation, and that's the way we usually talk about Corianton. He's Alma's kid who couldn't keep it in his pants.