Conflicts for a romance?

- a third person
- money
- conflicting world views or religions
- money
- conflicting thoughts on children
- conflicting thoughts on marriage
- money
- some bizarre secret on the part of one of the parties
- parents who don't approve
- politics
- major injury (one must decide whether to stay with the other)
- death
- did I mention money?

Need more ideas?

Cheers,
Michelle