The Smart Bitches have ranted about this before but I really wanted to throw in my $1.05.
A big thing, which I'm surprised they didn't cover is: What makes it a surprise?
A.) What reason did the heroine have for not telling the hero before they got naked? I mean, um, it's kinda a big deal. And even if she was hoping to hide the secret, why didn't she at least ask him to be gentle? That's not an unreasonable request and if the hero is not one to comply, then he's not much of a hero.
B.) What makes the hero assume the heroine is not a virgin? (Especially if it's a historical). Usually it's something stupid, like some bitch tells him the heroine was sleeping with someone else, or the heroine is so innocent about sex that she says something "wordly" and he misunderstands. So why doesn't he freakin' ASK her? This type of assumption is stupid. Also, with STDs or potential heirdoms on the line, it's a valid question.
C.) With the surprise virgin scenario, the sex is almost always bad. I HATE it when the characters have bad sex! It reminds me of the old 80's romances where the hero rapes the heroine and I spend the rest of the book wanting to castrate him.
D.) Speaking of bad sex, as the Smart Bitches already mentioned, afterward the hero almost always says he would have done it differently if he had known. So...um... he usually doesn't do foreplay? He's always rough in bed? What does he mean? Whether a woman's a virgin or not, it's not comfortable for the hero to just thrust right in unless she is very aroused. So the hero must be a terrible lay.
E.) The details of the deflowering are often wrong, like where the hymen is. Also, many women do not have a hymen by the time they lose their virginity. Many are born without one or lost it horseback riding or even riding a bike. And if they did have one, the first time can still be pleasurable if the guy is really gentle. I went on a rant about this stuff here.
My summation of this often irritating cliche is that the author needed a BIG MISUNDERSTANDING to create conflict between the characters and she was lazy about it.
That said, many of my favorite novels feature the surprise virgin. So I guess as long as the rest of the story is engaging, I'll let em get away with it.
What is your take on the surprise virgin? What romance cliches bother you the most?