This leap year presents us with a once-every-four-years opportunity for women to propose to their partners. The old tradition is quite outdated now, and women - thankfully - feel empowered enough to propose whenever they like.In fact, recent research from LoveHoney found that 35% of women think only being able to propose on 29 February is sexist. Take these female celebrities, for example. From Britney Spears to Elizabeth Taylor, these women bucked the trend and proposed to their other halves. We love to see it.