1.) When I spank him I am acting on the request of the Mother and the Grandfather to correct him and it involved the words of pop the pamper out of their mouths.
2.) If spanking is so wrong explain to me why I have a friend who is the Chief Magistrate for the State and know several State Troopers who have all said as long as you don't make it to where they can't sit down you can spank between the knees and the waist on the backside.
I am only asking cause I am hearing a lot of don't spank your child however I am hearing from people with the knowledge of the law in my state that its perfectly fine as long as you don't cross a certain point.
Spanking a 20month old isn't teaching them not to bite - it's teaching them that the way to deal with problems is by hitting others and that adults have permission to hit/hurt you if they want.
Think of this from a infant's/ toddler's eyes:
If he does something you see as wrong, you hit him (call whatever you want, it's still hitting). The cause and effect lesson he learns is: the way to deal with people who do something you don't like is to hit them. He then carries this learn with him, so when he plays with his friends and they take a toy he wants, or does something he doesn't like he uses the technique that you taught him - HE hits them (because you've shown him that hitting is the correct way to manage conflict)
The reality is that almost all toddlers go through a biting phases - for the most part they aren't trying to be mean, or hurt people... they're learning very important developmental lessons - including how their actions impact others, and how sensations work etc. For the first years of their lives they are ENCOURAGED to chew, bite etc ... because they're cutting teeth, learning to chew foods etc - each chewy/teething item, each food has a different "feel" when they bite it ... as do their fingers when they suck, chew on them. At a certain point they start wondering if how it feels to chew/bite other people's fingers etc - not to HURT them, just to see how it feels/what it does. Keep in mind that when they chew on their OWN fingers, they get instant feedback on how hard they're biting themselves - a built in "warning system" that they are going to hurt themselves, so they know to stop biting harder. This "warning" is completely absent if they chew/bite someone else's skin (of course) - however THEY don't understand that - they don't understand that in the way adults do - they don't necessarily understand that if they bite someone and you say it HURTS that it really HURTS YOU (because they're often thinking, "no, it's not hurting me at all ...and when I bit my fingers like this is DOESN'T hurt either - it must be a GAME!!"
The bottom line, is that biting is a developmental STAGE - is a NATURAL (very frustrating for the parent) stage, that DOES need to be managed of course - but honestly spanking isn't sending them an understandable message at all.
It's also worth pointing out that the only people in recent history who've ever been "allowed" to use spanking is parents/guardians (of which BTW, you're currently neither, and legally you could be in a HEAP of trouble for striking this kid because it's not yours). Daycare workers, preschool teachers, babysitters, nannies etc ... none of them are allowed to use any sort of physical punishment (spanking, slapping, hitting etc) - and honestly having looked after infants, toddlers, young children, teens for the last 15+years there has NEVER once been a time in which hitting/spanking was a "good way" or the most effective way to manage the problem. There is ALWAYS an alternative to hitting, always. It's up to the parent/caregiver to be mature and responsible enough to figure out a better means of correcting the child - in a way that makes sense to that child.
Hitting a child teaches that child that violence is the best solution ('act first, think later' management strategies)
Honestly I'd really recommend that you and your fiancee seriously consider taking some parenting classes. I'm not saying this because of the spanking (though it's certainly a factor) - but mainly because it will help you both become better parents to this child, give you strong skills and make sure you are working together in a way that is beneficial for the two of you as parents, as well as for this child. Taking parenting classes together also shows the grandparents that you are committed to raising this child together and using positive parenting methods. The classes will also give you material which you can then share with the grandparents so that everyone is on the "same page" and asserts the mother (and your) roles as parents, and theirs as grandparents.
Regarding the information you got that states as long as you don't hit them hard enough that they can't sit .... to be blunt - they're wrong. It might be their personal opinion, or it might be that if you were taken to court you might not be convicted of child abuse etc, but if you talk to child and family services they will tell you something VERY different than "you can hit them as long as you don't beat them hard enough that they can't sit".
Frankly, the idea that anyone would think it's alright to hit an infant/toddler - as long as they stop before they injure them to the point they physically are in so much pain that they can't sit (either due to bruising, beating the skin red, or in some cases because the blows have actaully broken/fracture the tailbone/coccyx) , that makes me ill. It reminds me too much of the "rule of thumb" - which long before it was a "saying" really was a "rule", which stated you could not hit/ beat your wife or children with a stick/switch that was thicker than your thumb)
I know that in most (if not all) of Canada, and the USA daycare workers, teachers, clergy, medical staff, and anyone who works with children is required by law to officially report any "suspicious: marks, bruises & signs of injury or abuse" as well as report if they see and adult hit/spank child, or if a child says they've been hit. I also know that you can spank a child where there are visible marks (redness, bruising etc) long before they are injured to the point they cannot sit down.
You may be interested in reading this article on the damage spanking can do:
Why not to spank The article also lists a number of books how to discipline without violence/spanking etc. many of which are available for loan at public libraries.