Sounds like the thrill of livin'—together—is gone. Rocker John Mellencamp is splitting with his wife of 18 years, reports PopEater. Mellencamp, 59, met then-model Elaine Irwin Mellencamp, 41, when she posed for the cover of his 1991 album, Whenever We Wanted. The two got engaged 10 weeks later. "John and Elaine Irwin Mellencamp are proud of their 20 years together and are very happy with their accomplishments both as parents and as a family," read their statement, released yesterday. No reason was given for the split. This was Mellencamp's third marriage. Click here to see the album cover.