The 'LA Ink' star - who split from her ex-fiance in September - slammed the 'Monster Garage' host in a post on her Facebook page, where she admits to being wrong not to trust people who warned her off Jesse.
In a post on the social networking site, entitled "Thank You, Jesse", Kat explained: "Today I encountered the 19th girl to add to the list of people Jesse cheated on me with during this last year.
"I know I deserve a big fat 'I told you so,' from everyone, and wish I didn't have to say, 'You all were more right than you'll ever know,' but you were.
"I kept going back and forth in my mind as to what the best way would be for me to release and let go of any residual feelings remaining from that toxic relationship.
"All of this may sound petty or immature to some, but I assure you this is coming from a place of pure honesty and love."
Jesse split from wife Sandra Bullock in April 2010 amid reports he had been unfaithful with multiple women - but Kat insists she just feels pity for her former fiance for "seeking validation" with other women.