Half Of Women Have Had Sex With Their Best Friend

TL;DR

50% of people report having had sex with a cross-sex friend, and 60% of romantic relationships begin as friendships.

Key Points

• 1.50% of people have had sex with at least one opposite-sex friend. Research by William Costello on 527 heterosexual and bisexual people found half reported romantic interest in a cross-sex friend, with the same proportion having acted on it.
• 2.Men and women fundamentally disagree on whether opposite-sex friendships are platonic. 81% of women said yes, compared to only 58% of men — women were three times more likely to view the friendship as purely platonic.
• 3.Men engage in wishful thinking about mutual attraction. A study cited from The Economist found men's assessments of how much their female friend fancies them match how much he fancies her, and are entirely unrelated to how she actually feels.
• 4.Women keep some opposite-sex friends as 'backup mates.' Both men and women select opposite-sex friends with the same traits they seek in romantic partners — protection, attractiveness, and resources — making 'just friends' claims statistically questionable.
• 5.Social media algorithms may be killing cross-sex friendships by creating gendered digital worlds. Young women grew up with Zoella and Facetune (used by 70–80% before posting on Instagram), while young men grew up on Runescape, leaving little common cultural ground.