Were Adam and Eve married, or were they cohabitating? What is the evidence?

Given that God created Eve especially for Adam, to be his helper, and God brought the woman to the man, that was the highest blessing from above any couple could hope for! God instructed the couple to be fruitful and to multiply and to fill the earth. Was there ever a bigger 'green light' for a man and woman to enjoy sex than that?

They became 'one flesh' as God said. Genesis 1:27-28. See also Genesis 2:22-24. They were united by God Himself, with His blessing. No need for any official to officiate - you don't get higher up than God Himself! No need for bits of paper to be signed (not that there was any such thing back then) because God had sealed their union.

There is no evidence they existed