[kjcmsw]

The taking of the allowance is good advice - if they get allowance. But 'allowance' doesn't always have to be monetary - it can also be the use of the car, etc., privileges to be lost. The car taken to school could be worth $10 - a replaced broken crock pot $29.99 --- lost car privilege 3x.

Having raised 4 children (3 girls and the remaining child at home: a boy age 14...with ADHD - yeah, God decided to punk me!!! lol) I can assure you punishments must "hurt" - if they can't feel it, it's useless. Not hitting, they have to give up something they like as a result of their actions.
That being said, if your boyfriend allows this to go on (some parents who see their kids part time are too lenient as not to have their limited time be a constant state of punishment/stress), it's most likely always going to go on.
You can try to talk to the boyfriend and reach a compromise but if he isn't willing, you need to learn to live with it or leave it - as in a situation of 'it's me or them' you will lose (if he's a decent father). No parent should be made to choose between their significant other and their children, no decent parent would choose.
Remind yourself he's a packaged deal, just as you would want it to be if the tables were turned.
But on the bright side they've only a got a few more years and then they'll be on their own --- if you can hang on until then, the rest will be a breeze.