I think this scene is strictly for character-relationship building (not to mention, sex sells). It consumates the marriage. It takes it to its natural peak. Now if there was a bed-humping scene then I'd say it went too far. FFC was showing the innocence, the physical matched with the emotional. It completes the bond between the characters and makes her death much more meaningful. Leaving that scene out would be like leaving all the shooting/murders out. We could surmise what happens, but seeing it completes the experience.