Relationship names

Regular
MLP =

AppleDash
AppleDash is the relationship between Applejack and Rainbow Dash

ApplePie
ApplePie is the relationship between Applejack and Pinkie Pie

FlutterDash
FlutterDash is the relationship between Fluttershy and Rainbow Dash

FlutterJack
FlutterJack is the relationship between Fluttershy and Applejack

FlutterPie
FlutterPie is the relationship between Fluttershy and Pinkie Pie

RainbowPie is the relationship between Pinkie Pie and Rainbow Dash

RariDash is the relationship between Rarity and Rainbow Dash

RariJack is the relationship between Rarity and Applejack

RariPie is the relationship between Rarity and Pinkie Pie

RariShy is the relationship between Rarity and Fluttershy

Twarity is the relationship between Twilight Sparkle and Rarity

TwiDash is the relationship between Twilight Sparkle and Rainbow Dash

TwiJack is the relationship between Twilight Sparkle and Applejack

Twinkie is the relationship between Twilight Sparkle and Pinkie Pie

TwiShy is the relationship between Twilight Sparkle and Fluttershy

Fluttercord is the relationship between Fluttershy and Discord

Twadence is the relationship between Twilight and Cadence

Twi Armor is the relationship between Twilight and Shining Armor

Twilestia is the relationship between Twilight and Celestia

Twiluna is the relationship between Twilight and Luna

Starlight Sparkle is the relationship between Twilight and Starlight

Discolight is the relationship between Discord and Twilight