Just tell her that you're not ready to take that step in the relationship. Tell her that you have too much respect for her AND her father.
My girlfriend wants to have sex with her but I'm not ready. We're both 16. But I'll get in trouble with her dad. Recently my girlfriend has been pushing for sex. I am afraid if we get to that point I won't be able to control myself?
I'm pretty sure a female teenager pushing for sex just means that she's trying to trick you into ruining your life, because if she gets pregnant, you'll be held responsible for it and you'll get punishments from MANY sources. Your girlfriend's parents, YOUR parents, life itself, since you'll need to spend most of your time taking care of the baby, and many other things.
You'll lose a lot of your money, time, privacy, and sanity trying to tend to taking care of a baby at that young of an age. You still have your whole life ahead of you - DON'T screw this up.
Tell me, is several minutes of pleasure worth all these costs/punishments?
You can't let girlfriends push you around
Their are other thing to do beside THAT!
If I learned anything it's to listen to adults
Funny if you were a female and your boyfriend was pushing for sex, you would get a lot of different answers and opinions in more detail. I'll bet if you read some of the questions from girls with this problem, you can also find some very helpful advice. After all we are people first, and people have principles they want to live by that are valid, no matter what parts they have available for pro-creation and satisfaction
I think it wise for you to not give in to her desires. Depending on where you live. In the US some states have laws against people under the age of 18 having sex, even if they are both under 18. In Wisconsin you both can be charged with a sex crime, and both treated as victim and perpetrator. So be very careful.