Need Relationship Advice

Me (17M) & my gf (17F) have been together for about 2 years...(Long distance for a few months now tho lol😅)

But I'm pretty sure that I don't want to marry her or make her my life partner...so what's the purpose of growing/ escalating it?

If one day I'm gonna be married to someone else why should I make her lose her innocence?