The couple - who have two children, Nick, 22, and Sophie, 19 - have been in a relationship for 28 years but are finally going to tie the knot on October 1 at a Beverly Hills hotel.
The ceremony is to be filmed for the seventh season of the musician's reality TV show 'Gene Simmons Family Jewels', which will document the pair as they prepare for their big day and the ceremony itself.
The 62-year-old bassist-and-singer popped the question while he and Shannon were on vacation in Belize, and the proposal was shown during the finale of the six season.
As he asked the former Playboy Playmate to be his wife, Gene said: "I come with so much baggage, but you're the only friend I've got. You're the only one I love ... and you're the only one I ever will love."
It seems things are a lot quieter for former hellraisers KISS these days.
The 59-year-old musician and Erin have two other children, Colin, four, and two-year-old Brianna, together, while the 'Rock and Roll All Nite' singer has a 16-year-old son, Evan, from a previous relationship.