The Guilt of Sleeping

As a Dad, why should I feel guilty about sleeping? I probably shouldn't, but I do!!!
Why? Because my wife is awake 2-3 times a night with the kids.
Here is a normal night:
Both kids are in bed by 8.30pm, a fantastic miracle, and something that allows Marisa and I to savour our evenings.
However, Gemma is usually awake at 2am and 4am to feed, sometimes not going back to bed for 30 minutes to an hour.
In addition, Henry has made a habit of waking up at 4-5am to come into our bed, and sleep until 6.30am.
The problem is that both children are in a "Mummy stage" at the moment. Henry will only cuddle up to his mother in bed at night, and Gemma obviously needs Marisa to be able to eat since she is still nursing. As a result, Marisa is up 3 times a night, and in the morning she wakes up with Henry barnacled to her, and his hands digging into both of her armpits.
I end up getting a full night of sleep most nights, with the occasional interruption of sometimes having to wake up once to bring a crying child to Marisa, before rolling over to go back to sleep.

This means that my wife spends most days looking like a zombie and telling me that she understands why the army use sleep deprivation as a form of torture. In the meantime. I wake up well rested and ready to work.

Even though there is very little I can do about this, I still feel extremely guilty about the lack of sleep my wife is getting compared to my long, relaxing, dream filled nights.
Add to this the fact that Gemma will only really fall asleep either while nursing or if Marisa has her in the sleepy wrap (see the blog on kids toys), and Henry insists on having Marisa put him to bed at all times.

I can read Henry a story, but apparently my voice singing a version of, "somewhere over the rainbow," where most of the words are "da da da" is not as harmonious as Marisa's fully loaded, in tune version.
In fact, I know so few lullaby's or sleep songs that I have on numerous occasions resorted to singing the famous Phoebe Buffet song from Friends, "Smelly Cat," in order to get Henry to sleep. You wont be surprised to know that this tactic is never successful and more often than not results in Henry calling for his mother.
I try to help where I can, but it can be very difficult. I know I am not the only Father having this problem, and I am sure that there will be a lot of mothers who are reading this thinking they would happily swap "problems" with me.
It is, however, something that bothers me on a daily basis, and an issue that I feel I need to remedy. I have not come up with a solution yet, but like the famous philosopher Metallica said, "I sleep with 1 eye open, holding my pillow tight."