how to see my wife's text messages?

I am going to answer this straight, because the wrong answer here costs people their case as well as their marriage.

Legally, in most jurisdictions you cannot read an adult partner's messages without their consent, even if you pay the phone bill and even if the number is on your account. In the US that falls under the federal Wiretap Act plus state statutes (California, Florida, Massachusetts and others are especially strict); in the UK, the Computer Misuse Act and the Regulation of Investigatory Powers Act; across the EU, GDPR and national criminal codes. Courts routinely exclude evidence gathered this way, and the spouse who gathered it can end up facing a civil claim or a criminal complaint — a worse outcome than the suspicion that started it.

What is actually available to you:

• Shared account access with consent — Apple Family Sharing, Google account sharing, or a family plan where both parties agree to visibility. Explicit, documented, and admissible.
• A forensic examiner working under a court order or with consent — for a divorce, this is the route a family lawyer will recommend. A licensed examiner's report carries weight; a screenshot from a spy app usually does not.
• Couples counselling or a mediator — not a technical answer, but the one that resolves the underlying question.
• Your own device and accounts — you can absolutely review your own phone records, your own cloud account, and any device you own outright.

What to avoid: stalkerware installed on her phone, "remote SMS reader" services (all phishing), and anything that asks for her Apple Account or Google password. Beyond the legal exposure, installing covert software on an intimate partner's device is a criminal offence in a growing number of jurisdictions, including under the EU's 2024 directive on cyberviolence.

Where legitimate monitoring fits is children's devices you administer. Ultimate Phone Spy covers Android, Windows and Mac for parents, installed visibly and documented (parental control features). It is not a tool for a partner's phone, and using it that way would put you on the wrong side of the law.