This has come up from time to time, and Michelle Obama's gaffe has made this an issue once again. Maybe some of us make single parenting look too good sometimes, I guess, because it seems everyone wants to call themselves one!
To be clear, if you are married to (or still in a relationship with) your child's other parent, you are NOT a single parent.
I don't care how many hours they work or how often they travel, they are spending their hours doing what's in your child(ren)'s best interest, as you are. You can still email, Skype, text or otherwise communicate openly about your children and your feelings about how you're parenting. You may disagree (and sometimes, from what others tell me, I appreciate that I don't have to get anyone else's approval or buy-in), but you know that even when you disagree, you both love your children and would do anything for them.
Single parents, whether divorced or by choice, do not have that. While I know that co-parenting is all the rage, and some do it quite well, it is still not the same as what married couples have. (Otherwise, I'm guessing, they probably wouldn't be divorced.)
I can't speak for all single parents, but I can say, as a divorced mom with full-time, sole legal custody, I cannot relate to you married mothers who try to tell me that you get it because your husband's out of town for a week or a month, or even a year. Sure, we might be able to relate on having to be two places at once, but you cannot relate to having no one who loves and cares for your children like you do.
One of the main reasons I divorced my husband was because he couldn't do that. He couldn't put their needs before his. I never had that, so I don't know what it feels like, and I could be suffering from my own delusion of the grass being greener, but it does sound pretty good. It wasn't the lack of his physical presence, but the loss of moral and emotional support that put me into therapy.
I'm not trying to say who has it better or worse, but I wish the married moms had more appreciation for what you do have. (And I'm guessing your spouse/partner doesn't like when you call yourself a "sometimes single parent," either.)
I don't know what to say when women complain about their husbands because they spent too much money on a present, or tried to solve a problem instead of just empathize, or forgot to pick up the dry cleaning. I know I'll sound like I'm trying to play the "woe is me" card if I say anything that tries to remind them that those problems are the good kinds of problems to have, but at the same time, it's bothersome to me to see women not appreciate just what good men they have in their lives.
And if you don't have that? Then maybe you really are a single parent, and I will be there with my moral and emotional support (and my therapist's number).
But if your spouse is merely physically absent, we can bond about how to overcome the challenges of too few hours in a day and being outnumbered, so long as you understand...and appreciate...the moral support of your spouse.