What are good survey questions to ask teens on the topic of sexual activity?

Naviee: What are good survey questions to ask teens on the topic of sexual activity?
I just need some good questions on a survey referring to teens and their sexual activity. Also it would be nice if you could add a little multiple choice along with it but if not questions simply are fine thanks!

Answers and Views:

Answer by <8^)
have you ever been pressured into having any type of sex

have you had any sex
if yes, do your parents know?

do you feel uncomfortable being put in a sexual situation

Answer by Lauren S
simple things,
how old when you lost it?
how often do you have sex.?
do you use protection?
what made you start?

Answer by Maria Elena
How old are you?
a) underage
b) legal age

Are you male or female?
a) male
b) female

Do you like sex?
a) yes
b) no

When did you last have sex?
a) over a year ago
b) a year ago
c) over 6 months ago
b) a month ago
c) just recently

Was it with someone you are currently in a relationship with?
a) yes
b) no

Were you forced to have sex?
a) yes
b) no

Surveys should be short, simple and easy to understand.