I dont mind if its the parents calling checking up on him/her but when friends call and they try to talk during our dinner/alone time it really puts a bad taste in my mouth and i probably would not ask this person out again depending on the call and how long she/he stays on the phone.. , i say its rude and if you know your going out to dinner with a person you can always excuse yourself to the bathroom or outside and chat? Do you guys agree??