still in love

best way to deal with seeing the boy you're in love with, be in love with someone else. We still talk everyday as friends since we broke up  but we were in quite an intense relationship for about 6 months and he took my virginity, still don't understand why we broke up and he's my first love  I just need to know how to get over him and how to see him with someone else . Especially because the girl he's talking to now is the girl I was insecure about our entire relationship.