Women becoming more sexual active

Finally the new era arrived! It is not so mocked anymore if girls also have sex with more guys than it was some years ago.

Mostly if you hear men and women talking there are two things
a) If a men had sex with a lot of girls he is ‘The hero, great, cool,…” or
b) If a women had sex with some guys, she is labeled as a slut

Why is it like that? Where is here the equality between men and women?
Good news, nowadays women have more sex with different guys and they are longer sexual active. ;)