1) Your Hubby needs to back off. Your son is a BABY, 7 months old! As Parents, we need to remember that it takes an ENTIRE life, for a child to "learn" about life and about "our" rules. It takes an entire life for US to teach them things. For a baby to be "disciplined" at this age..... is really jumping the gun. To me.
A Parent is either a "hammer" or a pair of wings for a child to soar with.
2) You are not doing anything "wrong." A baby is a baby... they do this.
3) Babies reject eating for various reasons: (a) they are not hungry (b) they are tired (c) they are teething (d) they are being made to eat when they don't want to (e) they have gas (f) they are not ready to eat (g) they are not at the stage when they "have" to eat 3 meals a day, like an older child. (g) perhaps 4 bites of food is ALL he can handle by the end of the day
*Also, keep in mind that for the 1st year of life... a baby's PRIMARY source of nutrition is breastmilk/formula... NOT solids.
* For a baby who is 7 months old, they are STILL adjusting to solids. AND, per my Pediatrician... eating 3 meals a day is a p-r-o-c-e-s-s.... it takes time to BUILD UP to that frequency. They don't HAVE TO have 3 meals a day... and you need to introduce it in time. Not overnight.
For some babies, intake amount varies at any given day or time of day... for some babies, eating 4 bites is enough. - "serving size" varies with each baby... it is in terms of "tablespoons" not how many "jars" they eat. A baby's stomach is tiny.
(4) There is a difference between disciplining and teaching/nurturing.... the expectations are different.
In the first scenario... it is 'expected' that the baby NOT do the 'wrong' behavior anymore. period.
In the second scenario... a baby is 'taught' boundaries... coaxed and nurtured in it... with the understanding that over time, AND age appropriately the baby will learn. Just not yet, and just not perfectly... everytime.
(5) A baby does not have impulse control... nor the abstract reasoning, at this age, to simply "stop' and understand everything and our instructions. But, over time, he/she will. A child does NOT have 'full' impulse control until about 3 years old... and even then, they will do things we don't want.
Kids will yell, tantrum, have melt-downs, reject things, etc. no matter what age. BUT, as it is appropriate for their age and stage of development.... you instill boundaries in them.
(6) Your baby is simply communicating. In the way that is for their age. And they should be "allowed" to express "frustration" as well... they need to learn that communicating is okay... many times it is us that don't understand THEM.
(7) I suggest teaching him 'sign language'.... so that YOU and he can communicate and express himself in a way that is more palpable. And of course, allow for a learning curve...
(8) Each child is different in temperament and personality. Some more strong willed than others. But at this age, yes may yell and cry or reject things. I really don't think, Hubby should 'expect' him to just silence himself at will and sit there and eat... or like a much older child.
Get a book...."what to expect the first year" by Arlene Eisenberg for example. Then, per each age stage... their behavior will make more sense to you... and bring on tips.
Good luck,