Although, I am aware there are many young women - teenage girls - where these stories are their first and only experience with sex. Because of that, I do wish they were a bit more realistic. Especially when having sexy times with someone the MC had only just met. STDs and pregnancy are real things.
Most of the stories I have read with sex, especially when I was younger, I leaned from Harry Potter fanfictions - and even in those a "protection spell" was used.
I think it is important to keep in mind who your audience is, and the message you are relaying to them.
1st off, CONDOMS DO NOT PROTECT YOU FROM EVERY STD.
I can't believe the author had [the main character] have sex with a player without a condom. LIKE REALLY? That was really immature.
I do tend to notice when I read a book the use of condoms. I know I told you that sex education is one of my causes. Therefore I really do feel safe saying that majority of authors have their characters practice safe sex.
I really do like new adult romance books and that's the genre that loves first time sex. Also one of the reasons why I'm not a fan of the reform player getting the girl. Condoms do not protect you from hpv which can cause cervical cancer. Herpes is another one that is not protected.
That being said these stories are all works of fiction. It's an escape and a fantasy. I don't really want to read about a girl giving oral sex and the next day she wakes up with cold sores.
I would like to believe that if you're reading a story that has sex in it, you're old enough to know about protection and know that what you're reading is a work of fiction. Of course, I'm sure there are some books that don't give readers a 'heads up' when there's going to be mature content and some younger girls or even boys may stumble across that mature read, so it could definitely be concerning among impressionable youth.
But then it brings up another issue for me. I don't think it's the writer's responsibility to teach their readers sex-ed, especially if it is fiction.
All that said, it's still important for both girls and boys to be aware of the posibilities of STDs and getting pregnant before you're ready, etc. I don't think it would hurt the romance if it's mentioned that they're using a condom, or maybe previously mentioned that one of them bought them beforehand. There's a lot of ways it could be incorporated without killing the mood.