An interesting question...... Along with it should be "why"? I do know its not always the husband though.. Blondie has mentioned it was she who awoke first, and im sure i have read others like it but id love to see an informal poll. I tend to think husbands may see things as elders that make them think and awaken but thats my personal bias speaking. Wifes may be subject to unjust treatment and thus awaken... They may also not be as invested as a male who has congregation responsiblities.
My rational mind says its likely subjective to the individuals in the couple but again i would love to see the informal poll results.....
in my case its obviously me who awoke first and there is little chance if any of the person im obligated too legally ever awaking