This paper presents a smart drinking cup proto- type platform for social sensing studies. Recording the dynamics of unscripted human interactions in social settings can be challenging and often requires the participants to wear external hardware. This leads to greater participant discomfort and behavioural changes. To address this, we propose a prototype for a smart sensing cup: a multi-sensor data collection device integrated into a drinking cup. A hydrostatic pressure sensor is used for the volume and temperature measurements of the con- tents of the cup. Orientation data is gathered with a three-axis accelerometer, measuring the pitch of the cup. Detection of whether the cup is being held by a participant is ensured using a capacitance sensor. The sampling rate for all sensors is 10 Hz and can store up to an hour of data on the device. Using the sensor data we are able to detect whether a cup is being held, identify drinking events and fluid intake and give live feedback on this using an LED.