Okay, you're a nice person, and your sister just wants to lie down and have three martinis while someone else deals with her kid for a MINUTE, GOD. But you're kind of lazy, basically, and you're looking for games that can be played while you operate a smartphone with the other hand. It's not your fault. It's not your fault. It's not your fault.
1. Do You Like My Hat?
Oh, my God, I can't believe I'm even telling you this one. I can't. It's so easy. Just put something on your head which is not normally found on heads. A book. A sweater. A piece of toast. Then say, super proudly, "do you like my hat?" And the toddler will WIG OUT. The first thing babies learn after coming into the world, apparently, is that things do not go on heads. After they yank it off your head, put it back on, or put a new object back on your head, and say EVEN MORE PROUDLY: "Do you like my hat?" Repeat.
2. Imma Push You
This one was inspired by the comedian John Mulaney. It's probably better not to explain the provenance to your sister, but you can watch the routine here (NSFW). At any rate, this one is dead easy: you're sitting, type-type-typing, the toddler stands in front of you, you say (in a fake-threatening voice): "IMMA PUSH YOU." Then you take the flat of your hand, and you place your hand on their chest, and you knock them over. They love it! They giggle hysterically. Repeat until they throw up from joy, then pass them back to mom.
3. Greeting Card Dance Party
Now, you have to PAY ATTENTION for this one, okay? Physically, you don't have to do anything, but you have to be a wee bit vigilant. Before you go over to Toddler Central, stop at any grocery or drug store that sells musical greeting cards. Buy one. It doesn't matter what it says. I've had great luck with cards playing the Kenny Loggins song from "Caddyshack," but I've also used "You Ain't Seen Nothin' Yet" and "Age of Aquarius" and "What is Love?" Hand the card to the toddler. Let them open and close it. If you want to put in a little effort, dance when the music is playing and freeze when it stops. Otherwise, they're fine on their own. If the music stops for more than a second or two, make sure they haven't disembowelled the card and started trying to swallow the machinery.
4. Fake Remote Control
Toddlers have an insatiable bloodlust for remote controls. Fact. They're also smarter than they look. You need to get a useless remote control (you probably have, like, nine that you don't use, honestly, or that control a speaker system the previous occupant of your apartment had). You can take out the batteries, but toddlers can usually tell by the weight that you're fucking with them. Now, here's where you have to up your game, okay? You need to make them think this remote is of great value to you. Pretend to use it. Then hide it somewhere dumb. Let them find it. Say: "No no, baby! Remotes are for grown-ups!" Take it away. Do that, like, four times, then pretend you haven't noticed they've found it. They'll be like Smaug. You will find them sleeping on their treasure. Also like Smaug, they WILL know if you move it.
5. Indiana Jones and the Exercise Ball of Doom
Classic. Best if you have a long hallway, but works anywhere. You do need an exercise ball (one of those ones you sit on to improve your core), but if your sister had a hippie birth, she probably used one to help open her cervix (ew). Roll the ball over the kid. It won't hurt them. Then, as they get up and run away, hurl it down the hall after them. It takes literally two pounds of force, you can just nudge it with your foot. They enjoy it more if you say "KALIIIIIIIIIIII!!!!!!!" as you do it.
6. Hide Things in Your Clothes
I don't really even need to explain this. I like to use a beeping baby monitor (one that's running out of juice and warning you to charge it) and stick it under my shirt. Then I lie on my back and read a magazine. The kid shakes you down and runs away with the monitor. Drag 'em back and repeat. If it's your kid, feel free to hide the monitor in your pants. If it isn't, keep it above the waist. Trust.