Almost all of my own books include LGBT relationships, the exception being one of my current novels-in-progress, 'Western Ways'. I normally avoid writing sex scenes like the plague, as I feel that:
They are embarrassing to write, never mind read.
I am not an adequate writer to create something which would not be cringeworthy.
I am far more interested in the relationships between people than what they do with their sweaty bits.
Accordingly, with two exceptions, I write about intimacy up to, as one comment put it, "the bedroom door". I have characters fall in love; they express that in physical ways; the details are not necessary. I have written about gay male couples, lesbians, trans women both straight and gay, trans men and cishet couples. I haven't explicitly covered bi or pan people, or non-binary folk, because I don't know enough about them.
In one horror story, I wrote an explicit sex scene because it was fundamental to the plot. In two other books, where there are particular aspects to the behaviour of a serial paedophile rapist, I included some details. I could see no way round those. In all other aspects, I write about people in love and all that is needed in terms of information is that they can smile at each other.
As an example of other writers and sex scenes, I would offer R.A. Heinlein. While I find his style very, very readable, his obsession with (and even more so, depiction of) sexual activity are risibly awful. I could add some books I have never read and never intend to, but this link will do:
http://www.fiftyshadesgenerator.com/?!
