While married to Kim Kardashian, Kris Humprhies claims that Kim kept in contact with Kayne West a lot. She apparently promised Kris that she would cease her communication with Kanye, but she never followed through on her word. Kris has stated that he was completely faithful while he was in his relationship with Kim Kardashian, but he highly doubts that she was too.

Kris believes that Kim and Kanye may have been fooling around together for a while.  He definitely feels as though they might have been involved with one another while he and Kim were married.  

Kris has major suspicions about the timing that Kim and Kayne chose to go public with their relationship. "Keeping Up with the Kardashians" is airing a new season in May, while Kanye just released a new album, so Kris feels as though their public announcement of them being an official item, may be a business tactic and less genuine than they let on.

Kris' message to Kanye West regarding having a successful relationship with Kim Kardashian:

"Good luck dude, you are going to need it." 

Source: globalgrind.com