text: Well, they're not best friends, but they're not enemies either.  They just don't visit each other like the way she does with Brooke Shields, or the way she hangs out with Posh Beckham.  I think there is definitely tension between them because Nicole is Tom's ex-wife after all.  I remember that in the beginning of Katie & Tom's relationship, it was reported that there was some sort of argument/disagreement/unpleasant talk between the 2 of them when Nicole called Tom's house once to talk to her 2 kids, Isabella & Connor, but Katie answered the phone.  But regardless, it has been said that Nicole wishes the newlyweds the best and a lifetime of happiness.  After all, Nicole is the children's mother and Katie is their step-mother, so they do have to get along.  At least, they are not having an ugly, nasty public feud like some people.