Charles Manson knows a thing or two about "till death do us part," so he's taking the marriage plunge.

The man convicted of slaughtering Sharon Tate and 6 others got a marriage license earlier this month. The 80-year-old murderer is marrying 26-year-old Afton Elaine Burton, who runs a Manson fan website.

Burton says the ceremony will go down next month behind prison walls. They can invite up to 10 free people.

There won't be any little Mansons running around ... he's not entitled to conjugal visits. Manson does have several grown children. Harvey interviewed one of his sons, back in his KCBS days.