Never, ever, under any circumstances, give your sister's best friend a lapdance on her birthday with a phone in your pocket. She will think it is part of your male anatomy, and lose the tiny sliver of respect she ever had for you. As a plus, (or minus, depends how you look at it) your sister will never stop laughing at you. #LFMBrother'sF

When your older sister's friend has a baby and you've just learned that babies bake in the oven for 9 months, don't start counting backwards to her conception, especially out loud, when you know she got married 6 months ago. #LFMyoungerstupiderself'sF

when drinking your orange drink that you left on a table at a party, make sure that you go for the right table. It will be you 17-year-old sisters and it will be spiked. #LFMF

When talking to your female best friend, after driving her sister in your car, when you just wandered around, the proper wording is "Your sister is fun to drive around with.", NOT "Your sister is fun to explore with." Especially if you and said friend are on the verge of a romantic relationship. #LFMF

When texting a girl you're interested in, it is best to make sure you're texting the right person. Your sister will be confused at first why you decided to text her out of the blue, and things will get a bit awkward before she realizes your mistake and clarifies who you're actually talking to. #LFMyBrother'sF

Never let your jokester sister book your bus trip. If you do, check your ticket to see what name she gave you. #LFMF

If you love Nutella, but your sister hasn't tried any, don't let her try any. She will adore it and end up eating it all, leaving you absolutely none #LFHerF