After lunch, they went to an electronics store because Lucille wanted a phone. However, Nicole told Lucille that she could not be allowed to have her own phone until she was twelve, so he did not want to get her one. With how kids nowadays with technology, he somewhat agreed. But then, Lucille talked about how the kids in her class thought of her as someone weird since she was the only one who did not have a phone.
Hearing that other kids her age, perceived his daughter weird just because she doesn't have her phone, he conceded. In exchange, he let her promise that the phone he got for her would still be subject to her mother's set of rules. And the phone would be merely used for contacting him or her mother. The phone won't interfere with her studies, no mobile games, and most importantly - no social media!
Nicole would probably give him a hard time, for getting her a phone - something that she was not allowed yet. According to her rule book.