The crime is rarely enforced, and repealing it has passed the Senate before. But Republicans in the House blocked it last year out of fear repeal could endanger sex trafficking cases because of a sexual immorality provision. This year, the bill has cleared the House and appears more likely to succeed.
Colorado's adultery law was created before statehood to reassure women that they would protected if their husbands cheated on them. The related crime of contributing to sexual immorality by providing a place for unmarried people to have sex was aimed at frontier-era flophouses.