Well now with that last post, tiredandlost, you DO get sympathy and understanding from me. Bending over backwards? Planning to wait up and take a bath with him....my my if I were your H all would be forgiven! (It's downright crazy how forgiving some men can be and how little it takes if you treat them right!)
I think you both need to develop a better appreciation for how hard the other works and how you each feel about the effort and value of your work. It's very easy on both sides to see only one's own part of the course of the day as being "rough work" and the spouse's part as being somehow easier. For example:
He goes to work, he's at work all day long. He puts in the time at work, plus the time commuting, plus any other incidentals (fuel refill, errands) along the way. All told that's the biggest part of his day, and he considers it all "work." Naturally the tendency is to feel entitled to do nothing but "play" once he gets home.
By the same token, maybe when he IS home, more of the time HE spends with the kids is of a recreational nature. He's more likely to be playing with them and entertaining them than he is to be dealing with diaper changes and cuts and scrapes and bad behavior as in things like kids embarrassing you in front of friends and neighbors with big mouths or short tempers! (And no I actually am childless and have no direct experience in this; I am only speculating!) The point? He's more apt to envision in his own mind, your time with the kids as being easier than it really is. From the other side of the fence, the grass is greener, and he thinks you've got it easy compared to what he's doing (all the more so if that involves being on a roof in the heat). You've got the A/C, maybe you're taking the kids to the pool...he can only dream of such things. Unfortunately it doesn't cross his mind that being at the pool with the kids requires constant vigilance and as much time packing supplies as he spends commuting to work! And if it's during the school year...wow! Maybe he thinks that other than a few loads of laundry, you're just sitting in front of the TV eating bonbons all day like Peggy Bundy from that old show Married With Children. (Here's where communication is necessary to better enlighten him).
When he gets home, he wants to relax; he feels he's put in his time, he now is entitled to kick back and relax. Yet you are staggering under your own day's events; you can't wait to dump some of it off on him. BAM- recipe for collision and hard feelings!
Important next step? Communication. In this case, more from you to him...letting him know...as objectively as possible and without placing "blame" on him....the facts about what goes on and why you're so tired. Help him understand just why his conclusion that your day is "easy" is not correct. Better yet...arrange for him to get more experience taking the kids for a whole day on his own, like you do...perhaps by getting away once in a while for a few hours on the weekend for some much-needed (and well deserved) relaxation.
Now what he (and I, and I'm sure a lot of men) still have a very difficult time understanding is how a woman can be "too tired" to want sex. Don't get me wrong...I certainly understand that women have a tendency to feel that way. So do all of us men. But if I can safely assume that a lot of men are like me in this regard, it's not something easily understood by the male brain. It's one of the "inexplicable mysteries of womankind" on a par with how women can enjoy talking so much, using 200,000 words to express what a man could easily communicate to another man with a few grunts (OK I exaggerate but you get my point). To a man, sex just plain feels good, and it's just plain fun. And contrary to what one person told me about his opinions of sex "done right," it doesn't have to be tiring in order to be good. There's room for variety depending on just how intense an experience one is in the mood for. So what people like me - and I"m sure Cemar and others - just can't fathom is how easily a woman can be out of the mood. From our vantage point it looks like all the planets have to be properly aligned and all else right with the universe...or the woman can't be turned on. Whereas with us, if the penis is hard we're ready to stick it in and start enjoying a wonderful time, and it doesn't matter if the house is on fire (well, almost.) If tiredness is a factor...hey, man can be on top and do the lion's share of the work and all woman has to do is lie back and enjoy herself. And we can't understand why she wouldn't want to enjoy it any more than we could understand her not wanting to enjoy a hot fudge sundae or a piece of chocolate! It's FUN! It's not supposed to be WORK! It's one of life's greatest and most enjoyable pleasures.
And when our wives don't respond that way, we wonder if there's something wrong with our woman. We're apt to assume other women would not have this problem, but would enjoy sex as much as we do...and we're apt to feel "shortchanged" or "cheated" or "ripped off" - and if we're Christian, not only by our wives but also by God (how COULD He let this happen after all the promises the Bible seemingly makes about the blessings of marital sex?)
Hence our frustration.
So - for what it's worth and if it is indeed possible (I'm not sure it is) - it might help to be able to communicate in whatever way it takes to get him to reasonably understand, without it coming across as an attack on him, how you could POSSIBLY not want to do something which to him is like the greatest pleasure / hot fudge sundae / shopping trip / romantic dinner / soul-searching conversation / (insert your own favorite personal pleasure here) he could possibly imagine in the whole universe.