disburse_wedding_spouse_host_activity_rewards

disburse_wedding_spouse_host_activity_rewards = {
	# for the loc
	save_scope_as = root_scope
	if = {
		limit = {
			root = scope:spouse_1
		}
		scope:spouse_2 = { save_scope_as = other_spouse }
	}
	else_if = {
		limit = {
			root = scope:spouse_2
		}
		scope:spouse_1 = { save_scope_as = other_spouse }
	}

	scope:activity = {
		if = {
			limit = {
				has_activity_option = {
					category = wedding_option_decoration
					option = wedding_decoration_good
				}
			}
			add_activity_log_entry = {
				key = host_wedding_decoration_good
				tags = { completed }
				score = 100
				# this line below adds the entry to the Effects section of the conclusion UI
				show_in_conclusion = yes
				character = scope:root_scope
				target = scope:other_spouse

				scope:root_scope = {
					add_character_modifier = {
						modifier = gwedding_magnificent_wedding_modifier
						years = 20
					}
				}
			}
		}
		else_if = {
			limit = {
				has_activity_option = {
					category = wedding_option_decoration
					option = wedding_decoration_normal
				}
			}
			custom_tooltip = host_wedding_decoration_normal
			add_activity_log_entry = {
				key = host_wedding_decoration_normal
				tags = { completed }
				score = 100
				# this line below adds the entry to the Effects section of the conclusion UI
				show_in_conclusion = yes
				character = scope:root_scope
				target = scope:other_spouse

				scope:root_scope = {
					add_character_modifier = {
						modifier = gwedding_grandiose_wedding_modifier
						years = 20
					}
				}
			}
		}
		else_if = {
			limit = {
				has_activity_option = {
					category = wedding_option_decoration
					option = wedding_decoration_bad
				}
			}
			custom_tooltip = host_wedding_decoration_bad
			add_activity_log_entry = {
				key = host_wedding_decoration_bad
				tags = { completed }
				score = 100
				# this line below adds the entry to the Effects section of the conclusion UI
				show_in_conclusion = yes
				character = scope:root_scope
				target = scope:other_spouse

				scope:root_scope = {
					add_character_modifier = {
						modifier = gwedding_grand_wedding_modifier
						years = 20
					}
				}
			}
		}
	}

	# LEGITIMACY GAIN FOR GRAND ACTIVITY PARTICIPATION - WEDDING
	grand_activity_participation_legitimacy_effect = yes
}

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