Strange can't help but raise an eyebrow at Sora's question. With a shake of his head, he asks, "Sora, if I wasn't sure, would I ask this in the first place?"

It's said as if it's the most obvious thing ever. Of course he's sure, if he didn't want Sora to show off, then he'd deflect the conversation with something like 'maybe later' or 'perhaps another time.'