Evolutionary psychologists suggest that women may be primed to look for ""good genes"" when good genes are the most useful. this explains why women are more drawn to men with deep voices and highly masculine faces when they are than at other times.

in the fertile period of her menstrual cycle

Explanation:

                 According to the evolutionary psychologists, the patterns of behavior have been evolved through a natural selection, similarly the physical characteristics have been evolved. Because of the natural selection or the adaptive behaviors or behaviors which increases the reproductive success, are  passed on from one generation to the next generation.

              Just before ovulation in a menstrual cycle, women's body has the highest level of estrogen in her body. The sexual desire in a women is influenced by the the estrogen hormone in women.

                Thus, women in the most fertile period are mostly attracted to the men with masculine faces and deep voices for search of good genes than when compared to other times.

because he had a big bear belly