Chapter 1

One week before the wedding, I stumbled across a sex tape of my sister and my fiancé.

On a porn site. The video already had over a hundred thousand likes.

One of the comments read: *"Whoa! Brother-in-law screwing his sister-in-law? Incest is so hot! Does her sister know?"*

The uploader had replied: *"Of course not! Her sister and I are getting married next week. Vivi just begged me for one last thrill before the wedding. I couldn't bring myself to say no."*

*"Was she the one who wanted the video posted?"*

*"Absolutely! Vivi said that with the video out there, she'd still have something to remember me by after I got married. What can I say—she loves me too much."*

I didn't hold back. I downloaded the video and sent it straight to Ethan.

……

I don't know how much time passed before my phone lit up again.

But it wasn't Ethan. It was Vivi.

*"Cassie, I made it—got to see my boyfriend. Slept with him right after his birthday. It was AMAZING!"*

She'd attached a photo. A shot from bed.

In it, her chest and shoulders were bare, and she was lying against the sheets. A man's right hand had slipped into the frame beside her.

I knew the ring on that man's finger. I knew it well.

Ethan had been sent to London for a year on assignment. Before he left, he'd proposed to me. He said we'd get married the moment he came back.

But now, there was no point in waiting. There wasn't going to be a wedding.

I stared at my chat with Vivi. I didn't reply. I didn't know what to say.

What was there to say? Demand to know why she was sleeping with her soon-to-be brother-in-law?

I'd always known Vivi had someone she was in love with.

I just never knew who.

For a whole year, she'd flown abroad two or three times a month, saying she was chasing a chance at love.

Even this trip—she'd flown out under the excuse of celebrating her boyfriend's birthday.

When I'd mentioned it to Ethan, he'd scoffed. *"Only someone as dumb as her would fly halfway across the world chasing a guy. Total lovesick idiot."*

He'd never had any patience for Vivi.

So I'd never let my mind go anywhere else—like the fact that Vivi's destination was always the same city Ethan lived in. Or that the man she was in love with just happened to share Ethan's birthday.

It never once occurred to me that he might be with Vivi.

The screen lit up.

A message from Ethan.

*"Cassie, wait until I get back. I'll explain everything."*

He was admitting it. Of course he was—with a video like that in my hands, there was no denying it.

My eyes drifted to the calendar on my desk. The 26th was circled in red, marked with an exclamation point.

That was the day Ethan came back. Two days from now.

Another message: *"Don't confront Vivi, okay? She'll feel terrible."*

Every word of it a shield around her.

My eyes burned. What did the two of them take me for?

*"She'll feel terrible? Terrible about screwing her own sister's fiancé?!"*