Afterwards I realised that it was a piece written with the benefit of hindsight: This is what I try to do. But when I started writing, I hadn't thought any of those ideas let alone formulated them into something close to rules. Instead I was making it all up as I went along.
I've always been interested in writing about relationships, so sex seemed a natural part of that. I wrote what I imagined my characters might be doing and what their emotions were without thinking of what my potential readers might think. It was only later that I realised that some writers become hamstrung by their worries of what their mother/father/partner/children/neighbours/friends might think. It cripples their writing, and no wonder, if that bunch is forever peering over their shoulder and commenting on what they've written.
Writing about sex should, ideally, be like having sex. You shouldn't write about sex if it makes you anxious or unhappy. It's not compulsory. It's an optional but, in my opinion, important element of human relationships. It should be something that feels natural and comfortable to you and happens in a non-judgmental environment. Let's face it, it's difficult to enjoy sex fully if you're worrying about your spare tyre or stretch marks, the same way that good writing is inhibited if you've got the critics sitting on your shoulder.
But the wonderful thing about writing about sex - about all writing in fact - is that you can write without inhibition because no one need see it. You have full control. Your characters can do whatever you fancy them doing, and they'll never answer back. And after it's all over, if you don't like it you can press the delete button, and there - It's gone. Your mother need never know.