What's the meaning of "be married to a cliché"?

Question

She’s married to a cliché.

I've come across with the phrase above in a novel.

Could you tell me please what the meaning of "be married to a cliché" is?

The fuller text is:

She sits down on the bed in the gloomy room and pulls her husband’s cell out of her pocket and looks at it. [...] Then she looks at the texts. She starts from the top of the list, ignoring names of people she knows, but then she sees a woman’s name she doesn’t recognize. She clicks on it and opens the text [...]

Idk. I have to go away this weekend with the nag.

When will I see you again?

[...] She fights tears and continues reading.

I miss you terribly!

Do you miss me?

Attached to the text is a picture of her, topless, with a shameless grin. Beverly stares at the photo, shocked to her core. She’s young, and gorgeous. A home-wrecker. She knows nothing about life at all. She can’t imagine what this girl sees in her husband. If she’s after money she’s going to be disappointed. He’s not going to have any left when she’s done with him, Beverly thinks furiously. She’s not going to divorce him. Surely this is just a temporary infatuation, a midlife fling. He’s made a mistake. A mistake that they can recover from. She doesn’t want to lose him. She needs him. She tabs up quickly through the rest of the texts to the beginning of the thread, anxious to see how long this has been going on. Only about a month. He met her at a bar. She’s married to a cliché. Well, now she knows. Her finger itches to send a text of her own to this bitch.

Answer 1

I see it like this. She's calling her husband a cliche.

cliché
2 : a hackneyed theme, characterization, or situation
(M-W)

Specifically, he's an unoriginal characterization of a middle-aged man with marital problems. How many times have you heard stories of a middle-aged man picking up a younger woman at a bar? Not very original, huh?

Answer 2

A cliché (sometimes cliche) in writing is something which is predictable, commonplace, dull, unimaginative, etc. The woman who has examined her husband's phone has discovered that he is all of those things.

cliché

noun

writing

an idea or expression that has been used too often and is often considered a sign of bad writing or old-fashioned thinking:

The story is shamelessly corny, and grownups will groan at its clichés.

Cliché