Trust is an essential element in any relationship. Not only in a love relationship, but certain degree of trust is necessary in a parent-child, pupil-teacher, boss-employee, friends, neighbors, etc. type of relationship. However, in a couple relationship, it is essential that each have faith in the other. Trust must be always present.
In short, you should not wonder or doubt if your spouse is telling the truth or not. Do you have an open communication and feel peace after talking to each other? Are you or your partner not always asking for clarification or for proof of what you say, where have you been and so on? Then there is real trust between you. Otherwise, one or the other, or both, will have to learn more about trust. It’s amazing how true Christian couples can have a 100 percent trust in their partners, and the reason is, most Christian couples understand the present and eternal consequences of lying to each other.
A very tiny lie can become a horrible brain eating monster. Seriously. There is no peace when hidden lies torment an otherwise peaceful soul.