Was Keith Richards his son's step-father? Did this make his son his step-father?

Not sure if you're confusing Keith Richards with Bill Wyman, but this is the only Stones related info I could find.

"At age 47, Bill Wyman, began a relationship with 13-year old Mandy Smith, with her mother's blessing. Six years later, they were married, but the marriage only lasted a year. Not long after, Bill's 30-year-old son, Stephen, married Mandy's mother, age 46. That made Stephen a stepfather to his former stepmother. If Bill and Mandy had remained married, Stephen would have been his father's father-in-law and his own grandfather."

celebrityrockstarguitars.com/rock/wyman.htm [no longer exists]