Mobile dating apps with geolocative function have gained popularity for fostering social, romantic and sexual connections between proximate strangers. Focusing on the experience of social time, this paper sheds light on users' experience on two popular gay mobile dating apps, namely Grindr and Jack'd. Based on in-depth interviews and focus-group discussions with 74 young gay men in Hong Kong, this paper identifies that the tempo and sequence produced by the specific affordances of apps are important to understanding users' experience. Specifically, accelerated tempo of interactions facilitated by constant connectivity, ubiquitous computing, geolocative function, and the apps' messaging system was seen to entail instantaneous and ephemeral relationships. The interface design, which foregrounds profile photos and backgrounds textual self-descriptions, structures the sequence of browsing and screening in a way that prioritizes physical appearance. This design feature was perceived to privilege users seeking casual hook-ups. These findings suggest that the temporality of browsing and exchange on apps is incongruous with the temporal norms prescribing formation of friendship and long-term romance. The violation of these normative expectations affects the perceived quality and satisfaction of app use, resulting in users' frustrations.