As a foreign man this can put you in a really tough spot, there definitely are some slutty girls out there who want to have sex with someone different without charging him to do so.
If you want to marvel at Ethiopian beautiful girls, areas around Mercato will grant you the best opportunity, because you will most certainly bump into bevy of beauties carrying baskets made of sisal going for shopping of grocery.
With the fall of the Derg, a laissez-faire approach was brought forth by the incumbent government and the streets, bars, clubs, and hotels were all fair game.