When should you resist the temptation of looking at your phone
While on a date
You're at a coffee shop with a nice person and they're telling you a not so fascinating story from their life, so you're thinking "I can totally listen AND check what's going on with #paintdrying!". Even if you can, just don't! It doesn't matter how you feel about the person, if you've decided to be there, you should show some basic respect. If there is something so important that it can't wait, it's better to go to the bathroom and check there. Just don't do it every five minutes.
This rule applies to pretty much all 1-on-1 interactions, but we can sort of give it a pass when it comes to friends you go out with regularly.
While at the movies
Turning off the sound of your device during a movie is a given, and luckily pretty much everyone does it. However, some people still feel like it's ok to use their phones. It's not. Even if you hold it close to you, to not disturb the person right behind you, your screen can still be seen from people sitting on either side. It's very distracting to have a bright dot somewhere in your peripheral vision while trying to focus on the movie. Do what you have to do during the trailers and then forget about your phone for 2 hours. That's what movies are for anyway.
While in a meeting
Unless your job depends on what's happening on your screen, you should avoid checking your phone during a meeting. Nothing says "I don't want to be here" more than constantly glancing at your phone. Chances are, everyone else doesn't want to be there too (unless it's a "Which of these new chips flavors should we release?" meeting). Would you open a book and start reading in the middle of a meeting? No. So don't use your phone either.
While at a funeral
This shouldn't even have to be mentioned, but we're going to anyway, because there's always that one person. Don't be that person. Even if you just buried your hated grandma that left you out of her will, keep your disrespect for later.
While at a sports game (baseball excluded)
This one is not so important, considering you can't really influence other people's experience with your phone, but we feel like it should be mentioned for your own good. You pay $60+ to go to a major sporting event, which usually lasts around 3 hours, and you can't help but whip out your phone every two minutes, or just hold it constantly, why? Okay, taking pictures is fine, sure. Some will say they only do it during downtime, so they don't really miss anything, but are you really that content deprived, while surrounded by thousands of people, that you must resort to your phone? Yeah, we thought so.
While at your wife's ultrasound appointment
The doctor is moving the ultrasound probe (that's right, I googled how it's called) over your wife's round belly, while she's staring at the monitor trying to make sense of the black and white images. The perfect time to check some memes, you might think! Wrong! Just as you open reddit, your wife looks at you to share the magical moment of seeing your child for the first time. And you've ruined it...
While your husband is sharing his latest accomplishment
After weeks of work and a case of beer, your husband is finally ready to reveal the Batman inspired bird house he built. While he's explaining how the feeder is squirrel-proof, you crave for some pictures of coffee mugs next to books, so you go for it! You look up just seconds later to see the disappointment in his eyes. He's probably not going to paint that fence anytime soon.
Now some people are thinking "Who are you to tell me how to use my phone, I'll do whatever I want with it!" And you know what, that's exactly the attitude that leads to the behavior mentioned above. What shows up on the internet, stays on the internet, it will still be there when you get to it later.