Second master's degree in another field without bachelors
Short answer is: Probably ok, so long as you demonstrate graduate-level competency and have good undergraduate grades in the adjacent field.

Long answer: Graduate work (at the Master's level) looks very different from undergraduate, so the key is demonstrating, via your application to the program (support from a faculty member in that area goes a long way too--so contacting such a person and discussing it with them before your application is important), that you are capable of self-learning and can pick up the introductory principles of the adjacent field as you go.