Collaborative Virtual Environments (CVE) with co-located or remote video communication functionality require a continuous experience of social presence. If, at any stage during the experience the communication interrupts presence then the CVE experience as a whole is affected - spatial presence is then decoupled from social presence. We present a solution to this problem by introducing the concept of a virtualized version of Google Glass™ called Virtual Glass. Virtual Glass is integrated into the CVE as a real-world metaphor for a communication device, one particularly suited for collaborative instructor-performer systems. Together with domain experts we developed a prototype system based on an instructor-performer architecture. In two studies with a total number of 115 participants we showed that the concept of Virtual Glass is effective, that it supports a high level of social presence and that the social presence for the performers is rated significantly higher than a standard picture-in-picture videoconferencing approach used for the performers. We present our experimental system, our studies, and the generalizability of our approach towards future uses.