SUBREDDIT: r/relationships
TITLE: Me [19 M] with my Girlfriend [18 F] for 2 months, how can i stay mentally loyal?
POST: Hello /r/relationships,

i need advice on how to stay completely loyal. I am dating my current Girlfriend for 2 months now. 

She is by heart the most caring and nice person i know, which makes this such an important topic for me. Our Sexlife is great and i couldnt ask for anything more regarding Sex.

Before we met and dated i was pretty much sleeping around and hooking up with random girls for approx. 2-3 years.

The first one and a half months we dated i didnt think of other girls at all but since 2-3 weeks i am almost daily thinking of old girls i hooked up with and how nice it was. 

My Problem is i really dont want to hurt her in any way. Neither do i want to cheat (stricly seen i already did by thinking of sex with other girls) nor do i want to tell her how i feel because im pretty sure i would hurt her just by telling her.

I thought it might have become a habit for me in those 2-3 years which makes it difficult now to not do it but im really not sure.

Did anyone experience something similar in their Life and got some advice? 

thanks in advance
TL;DR: 
Got a girlfriend after hooking up with random girls for 2-3 years but i am still thinking about old girls i used to hook up with all the time.