Man vs. Society
Romeo and Juliet are going against society. The Montagues and Capulets have had a long history of family feuds, and didn't want to have any of their relatives marry or get with anybody of the other family. They go against their mother and fathers' wishes by secretly marrying eachother.
"I take thee at thy word:
Call me but love, and I'll be new baptis'd;
Henceforth I never will be Romeo."
-Romeo (Act 2, Scene 2, Lines 47-49)
"I'll go along no such sight to be shown,
But to rejoice in splendour of mine own."
-Romeo (Act 1, Scene 2, Lines 102-103)
"His name is Romeo and a Montague,
The only son of your great enemy."
-Nurse (Act 4, Scene 1, Lines 89-120)
Friar Lawrence and Juliet go against society by planning to fake Juliets death, so Juliet wouldn't have to marry Paris, which is what her parents wanted her to do.
"I will not marry yet; and when I do, I swear it shall be Romeo, whom you know I hate, rather than Paris."
-Juliet (Act 3, Scene 5, Lines 121-123)
"This distilling liquor drink thou off, when presently through all thy veins shall run a cold and drowsy humor."
-Friar Lawrence (Act 4, Scene 1, Lines 93-96)
"If rather than marry ountry Paris, Thiy hast the strength of wil to slay myself."
-Juliet (Act 4, Scene 1, Lines 71-72)