Wallem, also an executive producer of "That '70s Show," among other projects, has been friends with the rocker for a decade and served as "best man" when Etheridge and then-Tammy Lynn Michaels exchanged vows in 2003 under what was then California's domestic partnership law, a People source said.
The friend who told the magazine that Etheridge and Wallem are now "in a committed relationship" also said Melissa and Tammy's breakup is going better than it was during the summer, when they were fighting over money and custody of their twins. "Everybody really is in a better place now," the source said.
Tammy Etheridge -- she makes it clear on her blog that the name remains the same -- whose split with Etheridge went public in April, wrote Tuesday that she had moved out in November 2009 because she was told "it would help," but "didn't know there was someone moving in as I was moving out."
She says that a package of a personal nature, mistakenly delivered to her rental house three weeks after moving out, was her clue that someone else was in the picture.
"I kept this to myself last summer," Tammy wrote. "Maybe I shouldn't have -- it would have explained another reason why there was so much bitterness in my cray-cray crazy blogs."