Do you ever feel like unleashing your wild side

Do you ever feel like you should unleash your wild side before getting into a real relationship that will most likely lead to marriage?
I have been with my girlfriend for 3 years through my teenage life and have been with no other lady,
She is perfect but i have been feeling like i should be single for a bit before i commit further into a relationship and unleash my wild side
and get all that out of the way and when i've had my fun settle down into a healthy relationship.
Don't get me wrong i love her but i just feel that i should be with more than one person in my life and would like to experiment. (as she has before me)
Say worse comes to worse and we divorce, I don't want to be a 40 year old one day that has only had one sexual partner all his life
I know people say its good for 2 people to go through life together just both people and i like that idea but i just feel like i should be with a few more girls before i get really serious with this girl.
I am 19 years old nearly 20 and not getting younger
I have asked for advice from close family and friends and they believe that I shouldn't be tied down so early in life as i should exploit my youth and there is plenty of time to spend with your girlfriend later on in life
Is there a way to tell this girl this and how so?

I agree with your family and friends....you should be single at this time in your life to enjoy all the variety that is out there for sure.

What to tell her? Breaking up is never easy but just be honest with her, take your lumps and move on.

I agree with smackle9. she might get hurt, but it's for the best that she should understand...

I'm a girl. 18. and never have a boyfriend (by choice)
and If I ever have(I'm not doubting, I'm actually
somewhat cute) ;) , I'm not gonna close my mind in thinking that
we will not last forever.

---There's no fairytale--
---Follow your instinct--

Yes, let it all out honey. You're 19 and you need to sow your royal oats. If you dont, when you do get married you'll probably end up regretting that you didnt get to enjoy having fun while you're young and then you may end up hurting whomever you're in a relationship with because you'll want to go out and get it and thats not fair to do on somebody elses time. Just tell her you need some space. You dont have to tell her why or all the details. Save her the hurt if you can. Shes still young just like you and may take it hard. So leave out the details. Just say you need space and time for yourself so you can grow.

Play it safe now. Dont go out there and get stupid.