In this paper, I introduce the concept of multimodal lies and examine its implications for definitions of lying. Traditional content-based definitions, such as those by Saul (2012), Carson (2006), and Stokke (2013, 2014), restrict lying to explicit assertions of a believed-false proposition. Commitment-based definitions, developed by Viebahn (2017, 2019, 2020, 2021), broaden this scope by including non-literal, presuppositional, and pictorial lies. However, both approaches remain limited to single expressive modes and do not fully explain how multimodal communication generates commitment. I argue that multimodal communicative acts can establish commitments equivalent to explicit assertions, challenging the assumption that lying is necessarily linguistic. By introducing multimodal lies, I aim to demonstrate their role in modal reinforcement, wherein multiple expressive modes converge to increase communicative commitment. This reinforcement reduces interpretative flexibility and constrains plausible deniability, strengthening the speaker's commitment to the conveyed content.