I would say it depends on the person's physical appearance and the type of clothing being worn. If the opposite gender does not find the person attractive and that person is not wearing revealing clothing or clothing that flatters their figure, the rating will be a 1. If there is one, but not the other, then a two. If the persons consists of both, then it can be a 3.
i dont really understand the basis of this question but i would say that its probably that its a low temptation activity, don't know where that would rate on your scale