Great answer. One thing that can help with tone is to imagine that the person cutting in line might not have done so on purpose - give them the benefit of the doubt. Maybe they didn't realize the line was so long, or maybe they were in line before but needed to go to the bathroom mid-way... You can just let them know in case they didn't intend to be rude. Also +1 to "excuse me" not "I'm sorry" in this case, your sister doesn't have to be sorry about anything. — qoba 1 min ago

It kind of sounds like you prefer being with 'Katie' more. I mean before people quit a relationship they often spend a lot of time with other people. If you are close friends with someone you are physically wrestling with, of the opposite sex, I'm not sure many spouses would not be jealous. — Mark Rogers 1 min ago

Yep, both refer to the same person. — Mitchell Raynard 1 min ago

@osuka_ Oh I understood I just wanted to hear it stated rather than implied. Now I can in good conscience say (to you at least): don’t be an ass. As much as someone (I, for example) see the metric system as useful and valuable, I can hardly switch to it by myself in the midst of a country that doesn’t. Ultimately, that means I don’t know how tall 151 cm is because I have no experience with it. Anyone being disagreeable to individuals over an ideological preference for a system they didn’t personally reject is to be a jerk. — Sojourner 1 min ago