Are there any child-proof pop-up books?

My eldest loves books with flaps and pull-out bits but her little brother ruins them all. This has caused so much grief in our household that I'm tempted not to buy any more (we certainly can't borrow them). Could you recommend robust pop-up books or alternatives that might entertain them both? Eric Hill's Where's Spot? was one of the very first flap books and remains one of the most successful because of its simplicity, and because the flaps are very well stuck down! But there are many excellent and more durable alternatives to flaps. Eric Carle's The Very Hungry Caterpillar has just one simple hole to explore, which is part of the reason it has endured, as does Janet and Allan Ahlberg's Peepo! board book, which has bits to touch. That's Not My Elephant and Noodle Loves to Eat are also delightfully tactile. Stories with buttons that make sounds are irresistible for kids, as are apps – try The Gruffalo or What the Ladybird Heard . But be warned, the noises can drive adults mad!