to be madly in love with when you are young
to have a crush on
to end the relationship
break up / split up
a person that you used to have a relationship with
ex
the person that you are engaged to be married to
fiancé / fiancée
to have an argument with smb and stop being friends
fall out
two people who are married or in a romantic relationship
couple
a friend from school or college
classmate
a person that you work with
colleague
to tell smb that their relationship is over
dump
to ask your lover to become your wife or your husband
propose
a person that you share a flat with
flatmate
to be attracted to smb
fancy
a very good friend that you can talk to about anything
close friend
your husband, wife, boyfriend, or girlfriend
partner