I don’t think the conversation Prince Charming had with Rumpelstiltskin warmed the former up to the latter as much as many would like–Rumpelstiltskin had still stolen his ring and forced him to fight a dragon in return for what was rightfully his in the beginning. And before that, he caused problems for both Snow White and Prince Charming.
But I think the conversation in A Land Without Magic did still help Prince Charming (for a moment) to feel a bit of understanding–they both had something in common: True Love. Both lost it at one point in their lives. For a moment, Prince Charming served as a confident to Rumpelstiltskin, who seemed almost a bit relieved to talk (to an extent) about Belle.
Nevertheless, I think his deal with Cinderella was one of the last straws for Prince Charming. The latter could not condone that, and who can really blame him?