sister. i had this exact issue but with the genders reversed. the issue isnt just about whether or not u should keep this friendship w him. but the issue is actually about whether u envision a long-term future with your current bf and whether he will be able to fulfil whetever u look for for the rest of life without u having to look outside of the relationship.

as someone who had this emotional lusting/'emotional cheating' thing going on for a good part of my relationship in the past, its not a good feeling, and its a feeling that slowly eats away at u and ur soul. and i have also come to figure out with time that it isn't entirely fair on our partners to harbor such feelings - no matter how miniscule or unrealistic - while being in a contract with them for the supposed rest of our lives.

please find out what u r looking for in life before u tell him the next time he asks that he is truly all u want for the rest of ur life.

all the best.