had_sex_with_effect

had_sex_with_effect = {
	save_scope_as = had_sex_root_character
	$CHARACTER$ = { save_scope_as = had_sex_with_effect_partner }

	# Error logging
	## Children should never run this effect.
	if = {
		limit = {
			OR = {
				scope:had_sex_root_character = { is_adult = no }
				scope:had_sex_with_effect_partner = { is_adult = no }
			}
		}
		error_log = "Trying to run had_sex_with_effect but one or more partners is a child"
	}
	## Did you forget to run the check for whether adultery was valid?
	if = {
		limit = {
			# Rarely, we may also want to block this check (e.g., seduction schemes or monogamous threesomes).
			NOT = { exists = scope:ignore_cheating_error_check }
		}
		# Check whether the root char is cheating.
		if = {
			limit = {
				scope:had_sex_root_character = {
					NOR = {
						is_consort_of = scope:had_sex_with_effect_partner
						has_relation_lover = scope:had_sex_with_effect_partner
					}
					might_cheat_on_every_partner_trigger = no
				}
			}
			# The weird structure here is so that we can use prev scope in loc to grab both chars.
			scope:had_sex_with_effect_partner = {
				scope:had_sex_root_character = { error_log = had_sex_with_effect.log.root_cheated_inappropriately }
			}
		}
		# Check whether their partner is cheating.
		## Though this does lead to potential duplication in the error log, where you'll get an entry for X cheating with Y _and_ for Y cheating with X, it is necessary: it's perfectly possible for one char to be cheating but the other not.
		if = {
			limit = {
				scope:had_sex_with_effect_partner = {
					NOR = {
						is_consort_of = scope:had_sex_root_character
						has_relation_lover = scope:had_sex_root_character
					}
					might_cheat_on_every_partner_trigger = no
				}
			}
			# The weird structure here is so that we can use prev scope in loc to grab both chars.
			scope:had_sex_root_character = {
				scope:had_sex_with_effect_partner = { error_log = had_sex_with_effect.log.target_cheated_inappropriately }
			}
		}
	}
	### Plus, remove the blocking scope we might have.
	clear_saved_scope = ignore_cheating_error_check

	if = {
		limit = { this = root }
		custom_tooltip = had_sex_with_effect.first_person.tt
	}
	else_if = {
		limit = { root = scope:had_sex_with_effect_partner }
		custom_tooltip = had_sex_with_effect.other_person.tt
	}
	else = {
		custom_tooltip = had_sex_with_effect.third_person.tt
	}

	if = {
		limit = {
			NOT = { exists = scope:no_sex_memory }
		}
		create_character_memory = {
			type = had_sex
			participants = {
				sex_partner = scope:had_sex_with_effect_partner
			}
		}
	}

	#Stress
	if = {
		limit = { # For use with events that add/remove more stress than these values, to avoid ugly tooltips
			NOT = {
				has_character_flag = no_sex_stress_loss
			}
		}
		$CHARACTER$ = {
			if = {
				limit = { this = root }
				stress_and_fulfillment_impact = {
					lustful = minor_stress_impact_loss
					rakish = minor_stress_impact_loss
				}
			}
			else = {
				hidden_effect = {
					stress_and_fulfillment_impact = {
						lustful = minor_stress_impact_loss
						rakish = minor_stress_impact_loss
					}
				}
			}
		}
		if = {
			limit = { this = root }
			stress_and_fulfillment_impact = {
				lustful = minor_stress_impact_loss
				rakish = minor_stress_impact_loss
			}
		}
		else = {
			hidden_effect = {
				stress_and_fulfillment_impact = {
					lustful = minor_stress_impact_loss
					rakish = minor_stress_impact_loss
				}
			}

As written in game/common/scripted_effects/00_romance_effects.txt.