George Crabtree meets Nina Bloom in From Buffalo With Love towards the end of Season 9. This is not a 'will they, won't they' relationship– they do it when George goes to question Nina in her dressing room for the first time.
Summary
While investigating a murder at the infamous burlesque hall The Star Room, George gets more than he ever thought possible from the talented and most desirable Nina Bloom.
Both Inspector Brackenreid and Murdoch try to discourage George from getting involved with the tempting burlesque dancer instead George is willingly seduced by Nina and will not let her go.