1. It's about a funny monster and a funnier princess, falling in love to/with each other.
(Which preposition do we have to use, 'with' or' to'? Are both OK?)
2. It's about a funny monster and a funnier princess, and they fall in love with each other.
(Does #1 mean #2? How could we paraphrase #1?)
#1 -- falling in love with each other.
#s 1 and 2 mean about the same thing. #1 is better since it's more concise (uses fewer words).
http://grammar.ccc.commnet.edu/grammar/concise.htm