Roger and joan have passion in their relationship, and they agree they will support each other. but when it comes to sharing their thoughts, they lack intimacy. their love is called

In this circumstance, their love is called fatuous love. 
Fatuous love refers to the type of love where the couple develop both passion and commitment toward one another, but they're lacking in intimacy.
Couples who are in this type of love, usually really happy in the early stage of their relationship but the fire will died out as the relationship move forward.