It's easy to talk to someone if you really love them. It's easier still when you know that they love you too. There's no reluctance to pick up the phone and call - day or night. The thought of spending time with them is not drudgery.
Unfaithfulness can hurt a relationship.
Nothing can break a heart faster than the realization that someone you love would rather be intimate with someone else. Hours spent with the TV - but minutes spent in prayer. You wouldn't dream of missing a single day in the office - but weeks go by between visits to the house of God. A relationship has to be worked at continuously. It must be a priority or other things will move in and usurp its place.