just tell them your parents decided for you to live with your dad a while so he can have time with you too
tell them you have to go to that school or your parole anklet goes off...
just tell them it was your choice.
Just say I've decided to live with my dad for a bit just to try something new then leave it at that. And they won't even know about you and your mum so they won't be able to ask
Just tell them that you had been living with your mom in that past and you thought it would be good to spend some time with your dad.
I heard this was a great school so was excited to come here, so tell me all the stuff that you wish someone had told you when you got here......
Tell them **** happens
Say, "Stuff happens" and change the subject.
tell you your parents are divorced you moved with your dad because you wanted to see your dad more.
Come up with a creative, off the wall, crazy unbelievable story, so unbelievable that everyone will know you are joking, and tell that instead. They will be so distracted from their laughter they will likely not pry.
if its a new school you gotta ask how well do you really know theese ppl take time to learn who you can really trust . thats why i say lie about it until you can find someone like that , and once the new wears off of you in their eyes the subject will drop completely
just make sure its something easy to remember but still be creative a humorous approach will anly last for so long with ppl you see everyday