In Tarot a cup represents feelings. Cup cards therefore refer to the relationships in your life. You can kind of break them down as follows:
Ace of Cups: Baby or Soul Mate
Two of Cups: Partnerships e.g. Best friends. Boyfriend/girlfriend. Boss/Employee.
Three of Cups: Your girlfriends or your mates
Four of Cups: Marriage
Five of Cups: Break Ups
Six of Cups: First love. Fantasy love (possibly too good to be true). Past love.
Seven of Cups: Choosing with your heart (or for money and possessions, which is it?)
Eight of Cups: Giving up on a relationship and looking for someone new.
Nine of Cups: Being satisfied with your relationships.
Ten of Cups: Immediate Family. (Ten of Pentacles is your extended family.)
Knight of Cups: Your ideal lover.
Any other suggestions?