**Participants** Participants consisted of 130 cohabiting, heterosexual romantic couples recruited online via advertisements posted on Kijiji, Facebook, through an email list of couples who had previously participated in research in our lab, and through flyers posted around the London, Ontario community. Data from 15 couples were excluded because one or both partners did not consent to participate in the study (n = 5), did not meet inclusion criteria (n = 4 non-monogamous, n = 1 same-sex couple, n = 1 does not speak/read English fluently, n = 4 one or both partners did not complete at least 3 diary surveys), resulting in a final sample of 115 couples. Partners ranged from 19-64 years of age (Myears = 30.78, SDyears = 8.99) and had been involved in their relationship from 5 months to 25.58 years (Myears = 6.83, SDyears = 5.87). Among participants, 41.74% of couples were dating, and 58.26% were common-law, engaged, or married. Among couples in the present study, 41.30% reported they have children, and among couples with children, most (82.11%) had one or two. **Procedure** This study occurred entirely online, and we used shortened versions of the focal measures in the daily portion of the diary study to reduce fatigue, increase efficiency, and minimize participant attrition (Bolger, Davis, & Rafaeli, 2003). Alphas will be calculated for each day, and the mean and range of alphas across all days will be presented. Participants were instructed to complete all surveys, including the 30-minute background survey on the first day of the study, the 10-minute daily surveys for 21 consecutive days (days 3-23), and the 30-minute post-diary survey (day 25), independently from their partner. To maximize participant compliance with the daily diary responses, reminder emails were sent to the participants who had not completed their diaries within 3 hours of their start time each day. On average, participants completed 18.87 diaries across the 21-day study (range = 4-21) for a total of 4339 diary surveys completed across all participants. Compensation for this study was pro-rated; participants could earn 2 CAD for taking the pretesting questionnaire, 1 CAD for each daily survey they contributed, and 2 CAD for taking the post-diary questionnaire, with a 10 CAD bonus given to participants who contributed to all study elements, for a maximum of 35 CAD per person. **Pre- and post-diary measures** **Relational boredom.** Relational boredom. Participants completed the RBS (Harasymchuk & Fehr, 2012) for both themselves and their perceptions of their partner. Items of the RBS will be mean aggregated, with higher scores indicating higher relational boredom. **Relationship satisfaction.** The seven item Relationship Assessment Scale measured participants’ relationship satisfaction (e.g. “How well does your partner meet your needs?”, “How good is your relationship compared to most?”; Hendrick, 1988). Possible responses were on a 5-point scale (1 = Not at all/Extremely poor, 5 = A great deal/Extremely good). Items will be mean aggregated, with higher scores indicating higher sexual satisfaction. **Commitment.** Four items assessed participants’ commitment (based on Rusbult et al., 1998), with possible responses on a 9-point scale (1 = Do not agree at all, 9 = Agree completely). Items will be mean aggregated, with higher scores indicating higher commitment. **Trust.** Trust was assessed with Rempel and colleagues’ (1985) 17-item measure rated on a 7-point scale (1 = strongly disagree, 7 = strongly agree) that taps the extent to which individuals believe their partner is dependable and honest (e.g., “My partner has proven to be trustworthy and I am willing to let him/her engage in activities which other partners find too threatening”). Items will be mean aggregated, with higher scores indicating higher commitment. **Relational boredom coping strategies.** Participants were provided with the following instructions “Please indicate how frequently you make an effort to incorporate each of the following behaviours into your relationship with your partner” and a list of seven relational boredom coping strategies (e.g. “Try new things with your partner”; developed based on the results of Harasymchuk & Fehr, 2010). Possible responses were on a 7-point scale (1 = Never, 7 = Always). Items will be mean aggregated, with higher scores indicating greater typical engagement in boredom coping strategies. **Relationship security.** Two items from the security subscale of the Need Fulfillment Scale (NFS; Mitchell, Bartholomew, & Cobb, 2014) assessed participants’ experiences of relationship security (“I feel secure in my relationship with my partner”, “I can count on my partner”). Possible responses were on a 9-point scale (1 = Never true, 9 = Always true). Items will be mean aggregated, with higher scores indicating greater relationship security. **Daily diary measures.** On odd numbered days during the 21-day daily experience portion of the study, participants completed the RBS (Harasymchuk & Fehr, 2012) for both themselves and their perceptions of their partner. Each day of the diary portion, participants answered shortened versions of the pre- and post-diary questionnaires: four items measuring their relationship satisfaction (based on Hendrick, 1988), three items regarding their commitment (based on Rusbult et al., 1998), three items regarding their trust for their partner, seven items regarding their use of boredom coping strategies that day (developed based on the results of Harasymchuk & Fehr, 2010), and two items regarding their relationship security that day (Mitchell et al., 2014). To ensure pre- and post-diary scores are comparable to the shortened daily versions, we will standardize all variables to create scores for each person each day (pretesting will represent day 1, and post-diary testing will represent day 25). Here we only report the measures used in this particular study. All measures included in the pre- and post-testing and the diary portion are reported on the general project page for the diary study at https://osf.io/42npz/.