Let's set some rules first.
The waifu(s) are LEGAL IN THEIR WORLD / CULTURE / SOCIETY... meaning, they reach "adulthood" when they become adventurers like most "other world" settings do it, for example it might be 15, 16, etc...
Polygamy is allowed in this world, since being adventurer is pretty dangerous occupation people don't really give a fuck how many people you marry.
LET'S ASSUME that some considerate amount of time has passed enough to build some sort of relationship with the waifu(s). Of course they have some affection towards you as well.
The waifu(s) are LEGAL IN THEIR WORLD / CULTURE / SOCIETY... meaning, they reach "adulthood" when they become adventurers like most "other world" settings do it, for example it might be 15, 16, etc...
Polygamy is allowed in this world, since being adventurer is pretty dangerous occupation people don't really give a fuck how many people you marry.
LET'S ASSUME that some considerate amount of time has passed enough to build some sort of relationship with the waifu(s). Of course they have some affection towards you as well.