Trust changes shape when a person starts needing proof for things once taken simply.

Trust is mostly the absence of checking. While it holds, you accept an account without verifying it, and the ease of that is the substance of the relationship rather than a bonus on top. When someone starts asking for receipts, timings, corroboration, something has already changed, and the requests are the symptom rather than the cause. It can happen for good reasons and it still marks a different arrangement between two people.

If you find yourself checking, say what worried you instead of quietly gathering evidence. And if you are being checked, asking what would settle it is better than treating the request as an insult.