Bruce Jenner -- Sons THRILLED With Separation From Kris

Bruce Jenner's 2 boys blame Kris Jenner for robbing them of their father and they are more than happy over the split ... sources connected to the family tell TMZ.

Brody and Brandon Jenner became estranged from their dad when he married Kris in 1991. They were raised by their mom, Linda Thompson and David Foster, who married Linda after she divorced Bruce. We're told the boys were devastated, and believed their real dad abandoned them.

What's more ... our sources say Brody and Brandon believe Kris is the one who convinced Bruce to jettison them, in favor of his new family. They have bitter feelings toward Kris, which endure even today.

We're told Brody and Brandon know ... Bruce didn't pay child support for 10 years, and after that only $1,500 a month. Again, they believe Kris was pulling the strings.

So now Bruce is living in Malibu, close to Brody and Brandon, and they are reconnecting with Bruce in what we're told is "an adult relationship."

Here's what no one will say out loud -- Bruce got sick of being alienated from his children, and one benefit of the separation is to rebuild and make good.

One final thing ... you may wonder why Brody and Brandon have appeared on "Keeping Up with the Kardashians," a show driven by Kris. We're told the boys have done everything they could to get close to their dad, and they felt if the show filled that bill ... so be it.