It's so much easier for boys right? - wrong
I think this was one of the messages from the film makers. That society still has double standards when it comes to male and female sexuality. It's all okay for boys to want and have sex but if a girl does she gets abuse for it. I'm not disagreeing with this but the boys tend to have different problems.
Consider this. Minnie wants sex. She really wants sex. So she starts having sex. Now many teenage boys her age would be the same. The lustful urges seep through them needing satiation. And yet they may well find it rather difficult to find anyone to have sex with them. Because 15 year old boys are not necessarily attractive to women. All Minnie has to do is flirt with guys and she can get what she wants. I suspect it's a bit more difficult for most boys. I do think one of the animosities between the sexes comes from how 14-15 year old boys who are just starting the dating game find themselves 'left on the shelf' by their female contemporaries who are into older hunky guys. And if those teenage girls don't want to have sex they don't have to and if they do then they can. But boys don't always get what they want.
I have to say as someone who was the smallest kid in my school year, getting interest in girls was near impossible. Not just at school but at university too. Years of sexual urges that couldn't be satisfied. Even now in my 30s I haven't got over those sexual hang ups. So my first thought on seeing Minnie having sex was lucky her! It's alright for some of us. I did like the film in many ways but it did bring back those teenage inadequacies right back to the forefront of my mind.