I have a list

1. Take pictures of our sex toys on snapchat and put emoji eyes and lips on them
2. Take a lot of nsfw but funny snapchat pics and videos
3. Reference the same inside jokes a ridiculous amount
4. Try to find the most disgusting or strangest videos possible
5. Make weird food or share weird food combinations
6. Compliment each other's pets as if they were humans
7. Watch strange documentaries. Especially anything by Louis Theroux. Someone usually falls asleep
8. Every so often one of my friends randomly sends me a picture of something with my head photoshopped on it, usually referencing an inside joke
9. Play never have I ever in this day and age
10. Start to play D&D but never really get into it. We've started quite a few times

There's probably more or better answers that I can't think of off the top of my head.