1. We've heard every twin line in the book.
Can you use the other one as a mirror? How do you know you're really you? It's so not the way to our hearts. Try chocolate instead.
2. Don't ask us a gazillion questions about what it's like to be a twin.
Yeah, the Olsen twins were pretty cool and so was The Parent Trap but to us it's all we know and honestly, we've had this conversation more times than we can count.
3. We will try and trick you into mixing us up.
It's all part of the fun. #TwinPrivileges.
4. We'll probably gang up on you with our true other half, and you'll lose.
Right or wrong, you might as well stop trying to win now. We've always got back up because our twin will totally take our side.
5. You have no choice but to be friends with our twin.
Awks if you don't like her.
6. And our twin's opinion is almost as important as our Dad's.
If you don't pass the twin test then basically your relationship is doomed (sorry about that, it's just life).
7. That threesome fantasy you have? Yeah, not going to happen.
Unless you're comfortable thinking about getting it on with your own siblings, don't even start the conversation.
8. People will ask you if you have a crush on our twin.
The answer is ALWAYS. NO.
9. And don't refer to us as "the twins" when we're together.
10. You'll always have to share us.
Twin dates are a thing and they're great. You'll just have to make sure the ones you take us on are even better.
12. Joint birthday presents are not okay, even if you are trying to get on our twin's good side.
Sharing a birthday can be bad enough! Extra brownie points for buying a separate present for our twin, though.
13. Getting our name wrong is never good, but mistaking it for our twin's name?
14. But any fights you have with us are nothing compared to those we have with our twin.
15. One minute we like each other, the next we hate each other.
Just stand back and wait until we start hugging again.
16. At the end of the day though, dating an identical twin is pretty great. DOUBLE THE FUN.
This article originally appeared on Cosmopolitan.co.uk. Minor edits have been made by the Cosmo.ph editors.