Hit me with your best shot

And yet, even if you witness those events, you can't know how any of that will play out in your marriage because your relationship becomes a part of the scenario.

That's not particularly good advice. Seeing someone at the absolute worst point of their life isn't "truly knowing someone". When my lifelong best friend died, I was in shambles for months. That's not who I am as a person, it's who I was during extreme loss.

Imagine breaking up with someone because you "saw their true nature" when they lost their dad.
I'm sorry for your loss.
it is a part of who you are though, how you handle loss.
Some people become destructive and never recover, and that is something you would ideally want to know about someone before a lifelong commitment.
- When you make a lifelong commitment, you work through tragedy together. You don't go "I don't like the way you're handling this, so fuck you, I'm out". You lift each other up when you're down. You know, for better, for worse, for richer, for poorer, in sickness and in health, and all that jazz.

Girl: Why won’t you marry me? Boy: Your family isn’t dead yet.

The other person will have the best indicator to NOT marry you in this case. And also a lot of problems...

You kill their father in front of them and they smile at you as your phone rings. "You should answer that... its probably your father with some news."

Wouldn't living with them for years first be sufficient in most cases?

No! Their therapist said you must wait until a major life crisis. Dafuq kind of advice is that? This person is a quack.
- I mean, people usually get sick a couple of times per year, not exactly a rare occurrence.

What if they don't have a loved one? Deceive them into loving you and then fake your own death. If they grieve for you good enough, miraculously come back to life?

Put a loaded pistol on a small table in a room. Have the pair try to install laminate flooring in that room which isn't plumb, level, or square.

If they both live then they can go to Stage 2: IKEA furniture assembly. One of the instruction pages is missing.

Bro if you put a loaded pistol on the table anywhere near me then it won't be loaded for long.
- Yes, carefully removing the bullets and installing a trigger lock is the right thing to do. Well done!
Wallpaper installation is also a fun activity for couples.

My mans is playin

That's what I generally do anyways so this should work out well.

I already tried all that!

Still didn’t work.