«Family»:
family,
family tree, relative, сlose relative, distant relative
father,
mother, parents/ child (children)/ son, daughter
brother,
sister/ twins, triplets, siblings
grandfather,
great grandfather, grandmother, great grandmother, grandchild, grandson, great
grandson, granddaughter, great granddaughter
uncle,
aunt/ nephew, niece
cousin,
second cousin
stepfather, stepmother, stepson, stepdaughter, stepchild, stepbrother, stepsister
«Relationships»:
boyfriend,
girlfriend,
ex-boyfriend, ex-girlfriend
sweetheart, mistress, lover
Mr.Right, flirt
fiancée,
fiance
wedding,
marriage, mixed marriage, marriage of convenience
bride,
bridegroom
the
best man, bridesmaid, matron of honour
spouse,
husband, wife
ex-husband, ex-wife
father-in-law,
mother-in-law, son-in-law, daughter-in-law, brother-in-law, sister-in-law
to be (a) single
to meet someone for the first time
to ask someone out
to chat (somebody) up
to go on a date
to flirt
to start / end a relationship with someone
to be involved in a romantic relationship
with anyone
to court /to woo smb.
to fall in love with someone
to go out with someone
to be taken
to propose to smb.
to get engaged to someone
to get married to someone
to fall out of love with someone
to be in an open relationship
to cheat on somebody
to be on a break
to dump smb.
to break/split up with someone
to divorce someone
Related websites:
http://www.englishteachermelanie.com/vocabulary-spotlight-on-relationships/
http://www.ieltsspeaking.co.uk/ielts-relationships-vocabulary/
http://www.bbc.co.uk/news/world-asia-24371673