Background <p>Floreciendo is a sexual and reproductive health program for Latina teens (14–18 years) and their female caregivers adapted from the evidence-based IMARA intervention. We report on our experience theater testing Floreciendo during the preparation phase of the multiphase optimization strategy (MOST) framework. Floreciendo includes four two-hour sessions (i.e., intervention components). Our aims were to: (1) examine the preliminary acceptability, appropriateness, and feasibility of the intervention components, including the acceptability of the implementation plan (i.e., logistics, strategies), and (2) systematically report on curriculum modifications made based on findings.</p> Methods <p>Using a community-based participatory research approach, we theater tested the program at a community organization over one weekend with three teen-caregiver dyads (<i>n</i> = 6) using mixed methods. Immediately following the delivery of each intervention component, teens and caregivers completed surveys and engaged in feedback sessions. Observers (<i>n</i> = 8) and facilitators (<i>n</i> = 2) completed surveys, recorded activity start and end times, and participated in a post-program discussion. Survey item ratings were on four-point Likert scales, with higher scores indicating more favorable results. Feedback informed subsequent curriculum modifications, which were documented using the FRAME.</p> Results <p>We found high satisfaction with the intervention components among all surveyed (<i>n</i> = 16) and with the implementation plan among teens and caregivers (<i>n</i> = 6) (≥ 3.7/4.0). Teens and caregivers described sessions as “educational,” “motivating,” “interactive,” and “fun”; all (100%; <i>n</i> = 6) reported that they would recommend the program to others. Teens and caregivers rated the appropriateness of the material and language/wording highly (4.0/4.0; <i>n</i> = 6), although caregivers expressed difficulty understanding “passive communication” given translation difficulties. Feasibility was also rated highly across groups (≥ 3.8/4.0; <i>n</i> = 16); 18% of activities were 10 + minutes longer than planned based on observer reports but the sessions overall remained within 2&#xa0;min of the allotted time. We modified the intervention components based on the feedback received. For example, we moved discussions about sex to come later in the foundational session to increase participant comfort.</p> Conclusions <p>Findings offer preliminary evidence of Floreciendo’s acceptability, appropriateness, and feasibility. Theater testing is a valuable tool for intervention adaptation and FRAME is useful for tracking curriculum modifications over time. MOST researchers could consider theater testing while carrying out preparation-phase activities.</p>