Well it was Sams idea to get others opinions but he knew Chris was less keen. All Sam really wanted was a genuine apology/to have his concerns heard. Chris however just wants to win the argument ( note the keeping score of his so cslled apology’s)
I think Sam had a last ditch at making peace but Chris is a vicious little drama queen. He knew he could use their difference over bringing it to the dinner party, as another point to score.
If he doesn’t rate Sam and his more basic lifestyle (as if), why even bother. Sam’s got the measure of him - Chris just wants to be right. Poor kids.