Gfs friend

I (m21) and my girlfriend (f20) have been dating for a couple years now and are long distance because of my school ( mechanical school).

I love her with all my heart and i could NEVER cheat on her but one of her friends who we went to highschool with i kinda like but its just like i get horny and go on vsco and let one out but i dont know how i feel about it.

I know her friend definitely likes me and such and such but i dont know how to feel. Shes just graduated and is 19 and ive known her for awhile but it just feels right. I dont know if i should keep just doing what im doing or try to initiate something with her and my gf.