"Really? That's all he did since day one? He didn't touch you inappropriately? No? Is he into rainbows?" Tilda asked what she really cared about after Chloe told her how she had been doing up to that point.
It was clear to see that she didn't care about what Chloe went through as long as she was safe. What she wanted to know was whether if Muku was the scumbag she thought he was. How could he not be with such good looks and have such a naive girl around him?
Anyone else in his situation might have long since turned into an animal. Especially after Chloe's evolution-driven glow-up that stunned even Tilda, who was no slouch herself.
So, finding out that Muku had been a gentleman from start to finish was rather surprising to her. Tilda was someone who was rarely wrong. For that reason, she got really irritated whenever she was wrong. Which led to her no-so-subtle dissing of Muku by accusing him of a certain thing that made his expression go dark.