Former athlete and TV personality Bruce Jenner is reportedly dating estranged wife Kris Jenner's best friend Ronda Kamihira.

Kris, 58, is said to be upset as her 64-year-old husband is dating Kamihira and it stings her because her best friend never told her that she has started dating Bruce, reports tmz.com.

Kris married Robert Kardashian in 1978 after which they split in 1991. The same year, she married Bruce.

Ronda has been a neighbour to Jenners for years in Hidden Hills, California.

Ronda, 51, is divorced and has two children.