Who texts, and with whom do they text? This article examines the use of texting using metered traffic data from a large dataset (nearly 400 million anonymous text messages). We ask 1) How much do different age groups use mobile phone based texting (SMS)? 2) How wide is the circle of texting partners for different age groups? 3) To which degree are texting relationships characterized by age and gender homophily? We find that that texting is hugely popular among teens compared to other age groups. Further, the number of persons with whom people text is quite small. About half of all text messages go to only five other persons. Finally, we find that there is pronounced homophily in terms of age and gender in texting relationships. These findings support previous claims that texting is an important element of teen culture and is an element in the construction of a bounded solidarity.