Falling For My Brother

I've been cared for by Sara's family since I was fifteen, and the other siblings in the family all get along well, except for Haden, the older brother in the family.
Haden is deep and inscrutable. Later, I came across something even scarier. Because after an ill-fated one-night stand, we got married...
"Even if you marry into Haden's family, with his child in your belly, you won't get your husband's love."
I was confused, why would I get Haden's love?
I would wish that Haden didn't come home every day.
We, as nominal husband and wife, should go our separate ways.
"You can go about your business, the kid and I are fine."
But one day, the husband, who is always busy outside and not just coming home every day, started rallying around me and the kid .
"Go to a party with me tomorrow."
"Didn't we agree not to announce our marriage in public, I'd rather not go but find someone else."
The man grinned, "What other people do I have besides you?" Then he walked away with a scowl on his face.
"What exactly do I have to do to get your love?"