What do you think about this

First let me say this situation is not something that I am going through. It's my best friend who is going through this and I'm curious as to what an outsider would think.

Please note I will not be using real names here.

So my best friend (Emma) has a sister (Taylor)

Taylor has been dating this guy (Chris) for almost 3 years and we all expected him to pop the question sooner or later. Unfortunately there was this disagreement about something and the two broke up. Fine. Life happens.

Meanwhile Emma starts dating some guy (who none of us have met yet)

Well turns out she's dating her sisters ex boyfriend Chris. She still hasn't told her family or even her sister. And Chris put a promise ring on her finger after dating in secret for 2 months. And to make it worse somehow she's wound up pregnant with HIS child. She's apparently already in her second trimester which means they conceived while he was dating Emma.

I'm beyond speechless and have no clue how to respond to her. I'm disappointed and personally I think that what she and Chris have done are wrong.

I need insight. Go