Objective: Engaging in practices of intimacy meant to develop and sustain intimacy can be beneficial for couples. Psychoactive substances such as 3,4-Methylenedioxymethamphetamine (MDMA) have shown to facilitate bonding within couples and it is hypothesised that classic psychedelics, due to their property to increase prosocial behaviours, can similarly promote interactional intimacy. This study explores shared experiences of altered states of consciousness within romantic couples and their impact on intimacy in relationships. Participants: Twelve participants (six couples) between 19 and 29 years of age who had used psychedelics with their current partner were recruited. Method: Qualitative data was gathered via simultaneous interviews with both members of a couple. The semi-structured interviews featured an in-depth exploration of multiple shared psychedelic experiences. Reflexive thematic analysis was employed to analyse the resulting transcripts. Results: Three themes with subsequent subthemes were identified, portraying couples' experiences during psychedelic-induced altered states of consciousness: navigating anxiety (subthemes: novelty, preparation, shifting environment, and calming presence), reshaping practices (subthemes: excessive worrying, spirited discussions, and straight talking), and encountering bliss (subthemes: meeting the unexpected, the beauty around us, leaving the everyday behind, and breaking through). Conclusions: Couples' experiences with classic psychedelics align with criteria for interactional intimacy (i.e., self-exposure, positive involvement, and shared understanding), but their distinct nature warrants a novel definition of psychedelic intimacy. The unique pair bonding during shared psychedelic experiences could be utilized by psychedelic-assisted couples therapy.