Coalescence by Susan X Meagher

In the first two books of this series, Jamie and Ryan forged a friendship, and realized that they had fallen deeply in love.

This book brings the two of them together for their honeymoon in idyllic Pebble Beach. Here they commit themselves to sharing their lives together. They begin to experience and explore the emotional and physical expressions of their love, as well as the conflicts and compromises that plague all new relationships.