They found each other in 1948 and had joined the Cullens in 1950 and were married after that. When they met Bella they were married but to the outside world they were acting as though they were only boyfriend and girlfriend.
Alice loves jasper but they do get maried but not at the moment they got maried centries ago, and one of jaspers friends thought that bella was his wife but she said no he is my brother in law. (it was the one that maked the passports, and jacobs drivers licens
Duh, she loves him. Why else would she take him along to find another half human in Breaking Dawn? She could of taken someone else. It also says in the books that they marry each other.
