You need to keep mood up on all girls but the most common reason you loose the option to private spank the girls is that you miss one. (I missed Lisa a few times couse its later after she washes dishes.) Mom will react to this by not offering private spanking till you do it again at least once in public ( Let me do this today option) It may even take an extra week before option appears again but make sue you never miss one privat spanking after telling mom you will take care of it
Someone said its about paying mom but that is only reguarding your privat spanking in her room and has nothing to do with spanking Lisa and Alice.