Tom Sandoval and Ariana Madix aren't working toward any sort of reconciliation ... we're told the damage done is just too much to overcome.
Sources close to the estranged couple tell us ... both Tom and Ariana understand their futures will not include the other, at least romantically, and they've made it known to their friends there's no hope of getting back together.
Of course, Tom is the one who derailed things, but sources close to him say he felt the relationship was on shaky ground in the months leading up to Ariana's discovery he was cheating on her with their costar, Raquel Leviss.
As for Ariana -- she was blindsided by the whole thing -- and we're told it's too great a hurdle to jump.
Tom issued an apology over the weekend, and weirdly left Ariana out of it -- telling his family, friends and business partners how sorry he was for the way he handled things.
Our sources say Ariana's been spending most of her time at the estranged couple's $2 million L.A. home. Tom's been in and out of the house ... notably when the two shot a scene for "Vanderpump Rules" this past Friday ... but we're told he hasn't been spending nights there.
At this point, it's unclear if either Tom or Ariana will keep the house, or if they'll just sell it.