At the beginning of season 5, Sam and Addison are back together, although they break up again as he is still not ready to commit to marriage and a family with her. Jake is hired at the practice, which at first makes Addison uncomfortable. Jake is a very gifted doctor whose speciality is helping women with fertility issues become pregnant.
In season 5, Sam and Addison rekindle their romance but ultimately break up due to his reluctance to commit to marriage and a family with her.  Jake's arrival at the practice causes initial discomfort for Addison. Jake is an exceptionally skilled doctor who specializes in assisting women facing fertility issues to conceive.