As long as they both agree on this formula and work toward that goal, keeping themselves always sincere and avoiding offenses, then it is not at all difficult to go back to Godhead together. This relationship is very intimate and has nothing whatsoever to do with external so-called romantic/sexual love. Such love may or may not be there, just as over-eating or over-sleeping may or may not be there. If it is there, it must eventually be given up. Therefore Prabhupada warns for devotees not to be overly attracted to one's wife or romantically involved. Chanakya Pandit also warns, "A beautiful wife is an enemy." Romance is not necessary for a spiritual relationship, but it can prevent the husband from ultimately being able to devote himself fully to Krsna. A very deep, spiritual relationship between husband and wife is only possible if sexual love is absent. A book called The New Celibacy goes into this in great detail and is recommended reading for devotees. What to speak of romance, Prabhupada says she must "faithfully serve her husband even if she doesn't like him." Westerners have this perverted idea that marriage is meant for romance, and so, if there is any break in the excitement, inevitable divorce follows. Prabhupada says however, "In the material world, there is no question of love-that marriage is actually a practical necessity, a duty." The wife may be attached to her husband if he is a devotee, but the husband has to be very careful not to be overly attached to his wife, since ultimately, he must become 100% attached to Krsna. That is the formula. Of course this formula varies somewhat according to ones status in life. The same strict rules that apply to the brahmins do not apply to the sudras, but anyone can go back to Godhead eventually, if he is sincere. It may not be in one lifetime, but as long as a couple are sincere, they will advance toward that goal.