set_random_sex_scene_location_effect

set_random_sex_scene_location_effect = {
	hidden_effect = {
		if = {
			limit = { NOT = { has_variable = sex_scene_location } }
			random_list = {
				20 = {
					set_variable = {
						name = sex_scene_location
						value = flag:garden
					}
				}
				20 = {
					set_variable = {
						name = sex_scene_location
						value = flag:private_chamber
					}
				}
				20 = {
					set_variable = {
						name = sex_scene_location
						value = flag:stable
					}
				}
				20 = {
					set_variable = {
						name = sex_scene_location
						value = flag:copse
					}
				}
				20 = {
					set_variable = {
						name = sex_scene_location
						value = flag:kitchen
					}
				}
			}
		}
	}
}

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