A boy in my class said: “girls always say no to sex at first even though they want sex. They want to be convinced.” Is that true?

There are lots of sayings like this one.
For example: “boys always have to take the first step”.
Or: “girls don’t know what they want”.
This is often not true.
Sometimes girls think: I shouldn’t say yes straight away.
Otherwise the boy might think I’m easy.
Regardless of the reason: the girl says no first.
She doesn’t quite trust you enough yet.

The situation may also be unclear with flirting.
It is not always easy to understand if somebody means ‘yes’ or ‘no’.
This is all part of flirting and it can be exciting.
It is important that you pay attention.
Otherwise you might hurt the other person.

This is why you must always respect a NO.
Nobody should be convinced to have sex.
Girls AND boys both want to be taken seriously.
If you aren’t sure: just ask.
Lots of girls really like this!
You can find more information here: http://www.echt-krass.info/trial_error.html