This paper applies Henri Bergson’s work on “affect” to romantic comedy, particularly the Hollywood film While You Were Sleeping (Turteltaub 1995). Bergson offers phenomenological descriptions of affects, from simple sensations to complex emotions, theorises them as qualitative multiplicities, and suggests how they afford an insight into nature as not a fixed essence but rather as durational processes of constant creative change, in which oppositions such as quality/quantity, belief/intelligence, myth/reality are productive forms of difference. Romantic comedies combine the sense of “nature”, which Bergson argues is the tendency of life to reproduce and develop itself, with an emphasis on emotional life, and these two things are linked. Romantic comedies are commonly described as formulaic, irrational, sentimental or fantastic, but each of these terms can be construed positively. Formulae refer to underlying natural cycles, reflecting the comic concern with rebirth and growth; the irrational, sentimental and fantastic refer not only to emotional states but also to particular mechanisms – Freud’s dream condensation and displacement, LeShan’s “magical thinking” and Moore’s “expressive behaviours”, all characteristic of situations of human significance where there is uncertainty, desire, and a gap between aim and result, or between sender and receiver. Expressive behaviours, both individual and social (e.g. rituals), attempt to “fill the gap” between subjects, when rationality fails, providing the social glue that makes human societies cohere. Finally, Bergson’s work on humour is examined in relation to the above themes. It is argued that the way Bergson theorises nature and affect as qualitative multiplicities connects them to emotional or expressive behaviours as manifest in romantic comedy and helps put them all on a firmer philosophical footing.