To unlock this achievement, you need to play as both a Male and a Female, to change your gender go to any Image As Designed. and pay 450$ for cosmetic surgery go to sex and hit female/male whichever sex you need to choose and play for 2 hours!
( EDIT ) this took me much much longer than 2 hours, so don't expect to unlock this straight after 2 hours it may be different from player to player but it took me about 10 hours as a female and 10 hours as a male for cheevo to pop
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If you have anything to say that could improve this solution feel free to comment and i'll take them into account, have a nice day!