Nothing grabs a man's eye more than a girl in a bikini with flat, sexy abs. Hot Bikini Abs are something women work hard to achieve and should be proud to show off. The hard work can pay off, as you can see below.
Six Pack Abs are fairly rare among women compared to men for two reasons. First, it's harder for women to reach the low body fat levels required for a six pack. Women need to get a body fat level of around 15% in order to get a six pack.
Second, six pack abs don't have an equal effect on men and women. Washboard abs on a man are highly desired by most women. On the other hand, a lot of men are not attracted to overly muscular women.
Women with six packs can be intimidating to some men, especially if they have a "keg" instead of a six pack.