Aaron Hung said:
My dad was really devastated when he found out she was dating him, our cultures are totally different too.
I don't mean this in an offensive way, but it sounds like you guys might have been just a little prejudice against this boyfriend from the beginning, since you said they've been together for 3 years and all that time you thought they would break up, plus maybe because of your cultural differences, you've had a hard time relating to him, or at least your dad has.
Before saying anything to your sister, I would really ask yourself how well you know this person and how much you know about their relationship, because maybe they're really in love and he makes her really happy and is a nice guy and treats her nicely.
You may also be absolutely correct, he may be a lazy good-for-nothing boyfriend that she'll have to support, but just make sure you're approaching your sister from the right frame of mind, or you'll most likely end up offending her.
Plus, it sounds like they're young, since she's in college (maybe early 20's I'm guessing), so maybe he's lost a few jobs for some stupid stuff, maybe he's not going to college for whatever reason right now, but it doesn't mean he'll be a loser for life or anything. Maybe he just hasn't found his path yet.
Anyway, that's my 2 cents, I love these types of Yakezie posts by the way.