I have 12 and 13 year old boys who are typically messy and untidy. I don't like to nag, but I cannot get them to clean up after themselves or tidy their bed or even put their clothes in the laundry!
I know a lot of you will probably say just don't do it, but I know from experience if I don't, the mess and laundry just pile up until it then turns into a 'project'- it doesn't go away and they don't magically start to turn into tidy boys!
Ultimately it is my house and I do not want to live in a pig sty so I regularly just clean up afterwards. Am I worrying too much? surely when they are older they will have no choice but to do it so should I just get off their case a bit?