LOS ANGELES – With their marriage under social-media scrutiny, Jada Pinkett Smith and Will Smith reaffirmed their commitment to each other as Pinkett Smith admitted to having a relationship with musician August Alsina when she and Smith were separated.In a one-on-one conversation Friday on Pinkett Smith's series “Red Table Talk,” she said she was reluctantly discussing Alsina's reported comments because of the public speculation they provoked.What started as a friendship and a family effort to help Alsina with his health about four years ago became a “different kind of entanglement” at a time when she and Smith thought their marriage was over, Pinkett Smith said.“An entanglement?