To be clear mine are long past nipple biting and twisting at four and six years old.
And, re-reading the thread, NOT ONE SINGLE POSTER has said they let their children get away with anything - I and others have clearly stated exactly what we have done in response to certain behaviours, in fact, but not necessarily with the miraculous resolution that some of you seem to think it will bring about. And Potol I quite clearly said in one of my posts that my two are just as rough with my DH so park your bizarre theory that only mothers receive/put up with rough behaviour.
What is not needed, or sometimes possible given the million other things you have to deal with as a parent, is escalation of discipline for every repeat infraction. What CheshireCat said basically. Nipple twisting/biting is the obvious example - that’s the behaviour of an older baby/young toddler. You can do exactly three things, and ALL of the posters here have done them - pull hand away, firm no (usually a loud yelp in the case of biting), put them down. This works quickly to stop this behaviour for some, obviously. It doesn’t work for others (didn’t for me), but as long as you consistently respond like this it really doesn’t matter because they grow out of it. There are far too many other exhausting issues to deal with, with far more serious consequences, than to waste your energies on devising heightened punishments for something they they naturally outgrow in a matter of months.
In terms of picking battles, I don’t accept for one second that you check every single aspect of your child’s behaviour. I just don’t - it’s too exhausting and doesn’t work anyway as behaviour modification is give and take. You tolerate certain negative behaviours as they may facilitate other more desirable behaviours. Take the example of my four year old hanging himself over my shoulders while I put his shoes on that I mentioned in my first post. It drives me Bat. Shit. But getting his shoes on means I need to be getting out the door. Prior to putting on his shoes, I will have to have nagged him and his brother repeatedly to put away their Lego, nagged them to put their snack rubbish in the bin, nagged them to get coats, nagged them to get the right kit ready for whatever activity we’re headed for, then chased DS2 around the house to actually get him close enough to get his shoes on. As long as it keeps him close enough to me to get the job done so we can get going, and because I’ve had enough of being the fishwife mum by that point, I put up with the infuriating draping. I really don’t think that’s negligent parenting or dooming him to a life of delinquency.