What would a guy do if he met his girlfriend's sister for the first time and found her prettier than his girlfriend?

Prettier doesn't make her more desirable necessarily. One can't go through life trying to "trade up" everytime you encounter someone that maybe looks prettier. A woman would be better off without you if that's the case.

That's just a cover, on a book. Maybe her sister is a psycho. 🤷‍♂️

No idea.. I would tell her it's nice to meet her and that's it. Smile and be nice. Idgf if a girl thinks she's prettier, it takes more than a pretty face to peak my interests

happened to me all the time. My sister puts me to shame

So?

He be a jerk if he said this to her and an even bigger one if he tried to date her.

Depends on the girls do they have attractive personalitys beauty is only skin deep

The decent thing to do is notice but not do anything.

Prettiness is entirely subjective and doesn't necessarily make a person attractive in any case. Personality counts for a lot in my book. Standards of so-called prettiness these days largely leave me cold. Anyway, he might be pug-ugly himself - it would be arrogant to assume another female would even be interested in him.

If it matters to him he isn’t in love with her

What he does isn't important. Hopefully. the sisters would shun him for being too shallow to deal with. He is NOT the real deal. He MIGHT get in a car accident and become horribly disfigured, and nobody would want him in their lives because, you know… ick.

SHEESH!

I think it would be hard for the guy to continue dating the less attractive sister. I bet he'd opt to break up.

My exs bro was hotter, all I did was look at photos of him. His personality wasnt to standard.

They were both good looking. But her sister never wore a bra so I started dating her I was very shallow when I was young

Go on about the day. Lol! He comes across plenty women prettier than his gf on a daily basis

id say hello and be nice and thats all , it's not about the looks

Bath them both, then f... them both one after the other is what I would do.

He would try to nail her too if he had the balls most likely.

Lmao me & my homegirl were just joking about this 😂😂

Looks are not everything

Threesome! Right now!😉

Nothing; at least I wouldn't.

Keep his mouth shut and fuck his girlfriend as her sister in his mind.

Depends on the dude, I know people I grew up with that will still try to smash both sisters at the same time