Students' relationships with their peers, teachers, and communities influence the ways in which they approach learning activities and the degree to which they benefit from them. Learning technologies, ranging from humanoid robots to text-based prompts on a computer screen, have a similar social influence on students. We envision a future in which AIED systems adaptively create social relationships with their learners in addition to modeling student learning and providing adaptive cognitive support. By deliberate design of the relationships between learners and systems, the systems can have maximal impact on student learning and engagement. This deliberate design would include careful consideration of the type of learning technology and its channels of communication with the learner, the broader context of the interaction, and the history of the relationship between the student and the learning technology. To achieve this vision, as a field, we will need to build understanding of how relationships form in human-technology settings, and how educational technologies should be advanced to support the assessment and monitoring of meaningful relationship factors over time.