HCI research has explored mobile technologies to support social activity and to support greater feelings of connectedness. Much of this has focused on different mobile devices, individual preferences and modes of use. Yet social activity and connectedness are about ongoing enactments of relationships across technologies. We propose the relational lens as a way to include a notion of relational tension in addition to individual preferences in the design and analysis of mobile communication technologies. We discuss three strategies people use to manage tensions in their relationships: selection, segmentation and integration. Our data show that use of social technologies can at times destabilize social relations and occasion relational tensions, forcing users to renegotiate how they enact these relationships.