I have a similar problem - but in reverse.
I am a stay at home mom.
Mon-Fri & I get up w/my 3 yr old daughter in the mornings (Daddy is long gone off to work) but, my husband gets up w/her on the weekends to give me a break.... (isn't he *awesome*?!)
It NEVER fails - every Mon., Tues., Wed. (and sometimes Thurs.) mornings, my daughter is calling out for Daddy in the morning & when she sees ME instead, all HELL breaks loose! The tears, the screaming "I want my Daddy!" and "Leave me alone!" is just heart wrenching for her (and a little hurtful to my ego, to be honest! lol).
It's 2 days of Daddy getting up with her and then 3-4 days of "recovery" to get back to normal routine - UGH!
Not to mention....we go about our daily routine of outings (errands, parks, museums, zoo, etc...) and she's completely fine, but then.....Daddy comes home from work and the entire "mood" of the household changes. All of a sudden, she can't go to the bathroom without Daddy, she can't eat a snack without Daddy sitting next to her, she can't play with her toys without Daddy in the room....All of these things she does with no complaint when Daddy is not home. Although Daddy is obliging, he is tired when he first gets home & needs a bit of down time.....THIS sends the little girl into a full blown fit.
All that said, when Daddy is home & she's throwing a fit because she wants him, not me, my husband & I simply don't give in....
"Daddy needs his time to unwind, so Mommy will go for a walk with you, Mommy will prepare the snack, Mommy will play Candy Land with you, and when Daddy's rested, then HE will do "A.B.& C." with you." Just taking a very matter-of-fact approach...sure, she still screams like a banshee for the first 5 minutes of our walk down the street, but she eventually gets over it when I point out the lizard sunning himself on a rock or the kitty sitting in the window of our neighbors home. :-)
We really feel that she behaves this way not only because she misses him throughout the day but, FRANKLY, Daddy is a pushover & will do basically whatever she wants him to! LOL
Maybe you are this way w/your boy? Doing everything for him, catering to him, talking & explaining these situations too much instead of just going about your business, etc...? I'm not being judgmental, REALLY I'm not....Just something for you to think about.
Of course kids are creatures of habit - it makes them feel secure!
Of course they like things "just so" - it makes their world make sense!
Of course they want undivided attention - it makes them feel special!
But they need to learn that BOTH of their parents are capable of giving them that love, time and attention...it may not be the "same" as the other parent, but that's the BEAUTY of it! Each parent has wonderful qualities to contribute to their child :-)
I think the parenting class is a GREAT idea for both you and your hubby....
Especially since you say that he may still be "uncomfortable" with his parenting style. Trust me, the MORE one on one time he gets with your boy, he AND your son will work out their own way of "being" together. And if your man is concerned that you just want to duck out for more "me" time, compromise by playing a family game together for a bit, and then go for a walk (or run errands, or make a phone call) alone. Give your man a chance to work it out with your boy & it will be fine ! :-)