This research examines the efficacy of an individually-delivered intervention tailored for YMSM in relationships. The intervention - termed PARTNER - utilizes a brief (4 session) motivational interviewing format to target Pre-Exposure Prophylaxis (PrEP) uptake/adherence, HIV transmission risk behavior, and associated drug use.

This study aims to evaluate a individual-focused intervention with an integrated focus on drug use and HIV prevention, including uptake of and adherence to PrEP. The investigators will recruit a sample of 240 partnered individuals.

Recruitment occurs using a mix of in-person and Internet recruitment. Outreach workers will visit bars and events in the New York City area to recruit participants. Also,information on our project will be posted on social media sites (e.g.,Facebook, Grindr, Scruff). Interested individuals will complete a brief online screener to assess eligibility. A telephone screener will be conducted with participants who are preliminarily eligible based upon online screener responses. Participants who are eligible based upon telephone screening responses will be sent an email. The email contains a link for them to access the baseline online survey. It provides information which introduces the study to the recruited partner and a link to the baseline survey online. If participants indicate intimate partner violence (IPV) on the online baseline survey, participants will be rendered ineligible. Only the participant that indicated experiencing IPV will be given a list of local referrals to access IPV-related services.

An in-person baseline assessment appointment will be scheduled after both participants have completed the online survey.

The in-person baseline assessment appointment consists of four components; written consent, a computer-assisted self interview (CASI), a timeline follow back interview, and biological testing.

Written consent is obtained prior to the start of any in-person baseline activity. Participants additionally complete a computer-assisted self interview (CASI). After this, participants will independently complete a TFLB. TLFB is a semi-structured interview to collect retrospective event-level data on drug use, sexual behavior and PrEP adherence (for those on PrEP) in the past 30 days.

The final part of the in-person baseline assessment consists of biological testing for STI (gonorrhea & chlamydia via urinalysis and rectal swabs), drug testing via 5-panel fingernail drug assay via finger or toe nail clippings. Drugs tested are 5 major drugs: Amphetamines, Cannabinoids, Cocaine, Opiates, and Phencyclidine (PCP). HIV testing will consist of a finder prick test using the Alere Determine HIV-1/2 Ag/Ab Combo test. Participants indicating current PrEP use will receive an HIV test via blood draw for a laboratory immunoassay. Participants indicating current PrEP give an additional blood sample and fingernail sample to examine PrEP adherence using a dried blood spot for western blot analysis and fingernail assay.

After the baseline assessment, participants will be randomized to receive their first PARTNER or Education session, of which will occur immediately following their baseline assessment.

The study will employ a stratified randomization procedure using an algorithm via Qualtrics. Participants will be randomized using three couple-level criteria as reported by the participant. Participants will be randomized based on relationship length difference (less than 2 years versus 2 or more), age difference (less than 3 years versus 3 or more), racial difference (both white versus all others combinations), PrEP use (Participant reports current PrEP use versus does not report current use).

Each of the intervention arms consists of 4 sessions that occur once a week for four consecutive weeks.

All participants complete a 3-month, 6-month, 9-month, and 12-month follow ups. At the 3 month follow up (post baseline assessment), participants complete a survey with a TLFB, fingernail specimen collection for drug use. For participants indicating current PrEP use, participants and give blood for a dried blood spot analysis and an additional fingernail sample to test for PrEP uptake/adherence.

At the 6 month follow up month follow up (post baseline assessment), participants complete a survey with a TLFB, fingernail specimen collection for drug use, biological testing for STI (gonorrhea & chlamydia via urinalysis and rectal swabs) and HIV testing using the Alere Determine HIV-1/2 Ag/Ab Combo test. Participants indicating current PrEP use will receive an HIV test via blood draw for a laboratory immunoassay Also, for participants indicating current PrEP use, participants and give blood for a dried blood spot analysis and an additional fingernail sample to test for PrEP uptake/adherence.

At the 9 month follow up (post baseline assessment), participants complete a survey with a TLFB, fingernail specimen collection for drug use. For participants indicating current PrEP use, participants and give blood for a dried blood spot analysis and an additional fingernail sample to test for PrEP uptake/adherence.

At final assessment (12 month follow up post baseline assessment), participants complete a survey with a TLFB, fingernail specimen collection for drug use, biological testing for STI (gonorrhea & chlamydia via urinalysis and rectal swabs) and HIV testing using the Alere Determine HIV-1/2 Ag/Ab Combo test. Participants indicating current PrEP use will receive an HIV test via blood draw for a laboratory immunoassay Also, for participants indicating current PrEP use, participants and give blood for a dried blood spot analysis and an additional fingernail sample to test for PrEP uptake/adherence.

Inclusion Criteria:

• 18 to 29 years of age (inclusive);
• Main partner must be aged 18 or older.
• Must be in a main partner relationship with another male (duration ≥ 1 months);
• HIV-negative serostatus (confirmed by rapid test);
• Recent (past 30 day) use of at least one of the substances identified as most commonly used by YMSM (marijuana, cocaine, methamphetamine, heroin or other opiates, MDMA, psychedelics, GHB, and/or ketamine);
• Sexual behavior meeting CDC criteria for PrEP candidacy (TRB with a casual partner in the past 30 days or TRB with a non-monogamous or serodiscordant main partner).
• Participants must reside in the NYC metro area
• Ability to communicate in English

Exclusion Criteria:

• Unstable, serious psychiatric symptoms (assessed by the Psychotic Disorder subsection of the Structured Clinical Interview for DSM-IV);
• Current suicidal/homicidal ideation;
• Evidence of gross cognitive impairment (a score of <24 on the mini-mental state examination)
• A history of severe physical or sexual Intimate Partner Violence (IPV) victimization in the current relationship in which participants report not currently feeling "safe" in their relationship and/or coerced to participate in the study.

Both gender at birth and current self-identified gender must be male.

12 months