I cant imagine not giving a client his full time, but my recommendation is to communicate in a direct but kind way. You can say something like, “ I really enjoy your massage, but do you know what would make it 10 times better? If you didn’t check your phone while warming up the oil, and if you gaave me the full time each session”. This will give him the chance and choice to do better. Hopefully, he’ll make the adjustments, if not, then you can nake the choice to continue seeing him or move on. Problem solved.