Maths tutor offered to take both boys together at a discount. They can't share a room for ten minutes

The elder one's tutor comes home twice a week. She has offered to add the younger one in the same hour, each working at his own level, for a reduced fee for both. On paper it makes sense. In practice they'll be kicking each other under the table by minute five. Has anyone made a shared tuition slot work for siblings three years apart? Or is it better to pay for two separate hours and keep the peace 🤷