There are no required factors! There isn't a specific formula! There just needs to be a certain level of a varying number of behaviors in coordination with an agreement!

[Akiha's face is just getting redder and redder. She's flustered enough about this subject that she might be pulling a bit on Lambda's hair as she continues to brush it.]

J-just call it 'sleeping together'. That applies to any couple that are having sex regardless of the type of r-relationship.