Image: Howard Wise/JPI; CBS

At the Abbott house, Jack and Nick discuss how perfect the day will be. Billy and Phyllis arrive when Nick’s in the other room. Jack’s pleased Billy will go to rehab tomorrow. Billy thanks Jack for the money and complains about Ashley. Jack feels it’s complicated, but Billy insists she’s only thought of herself. Nick reappears. He’s fine with Billy attending the wedding. Billy advises him to treat Sharon well. In a moment alone, Nick assures Phyllis he won’t tell Sharon about their night together. She reminds him their fates may lay in other’s hands. Nick doesn’t think anyone will talk. Phyllis wishes Nick all the happiness in the world. After Phyllis and Billy leave, Jack approves of Nick’s vows and they have a heartfelt conversation. Jack, chuckling, warns him of the wedding day rule – never disappoint the bride.

In Sharon’s house, Mariah worries she did the wrong thing by telling her mom about Nick and Phyllis. Sharon calmly assures her daughter she won’t fall apart or break down – she just needs to figure out what comes next. They debate whether Summer’s information is reliable, but Mariah adds Kyle confirmed it. She reminds Sharon of the day she took off her ring. Sharon recalls Nick didn’t come home that night. Sharon rants about the last affair, and Phyllis. Mariah’s sure it was a one-time thing. Sharon murmurs that it ceased to be a one-time thing a long time ago. Mariah insists Nick loves her. Sharon cries that they loved each other the last time too. She debates whether to cut ties or accept Nick made a mistake and wants her more than anyone else. Mariah’s slightly taken aback when she announces the wedding will happen today – it’s what she wants. She asks Mariah to go to the church and pretend this conversation never happened. Mariah thinks Sharon needs time, but the doorbell rings – it’s Summer, (played by Bayley Corman), who wonders if everything’s under control. Mariah says everything’s great. Sharon asserts, “Never better.” Faith appears, and Mariah warns Summer quietly to keep Nick and Phyllis’ secret to herself. Summer feels her dad and Sharon will never last anyway. Sharon sends them on ahead of her.

More: Y&R blog on Sharon’s bachelorette party

At the Club, Arturo admires Abby’s appearance as she disconnects from updating Victoria on Billy. They canoodle and discuss Nick and Sharon’s upcoming wedding. Abby marvels at Sharon’s capacity for forgiveness, and enthuses that she loves a good wedding. She assures Arturo she meant other people’s, and he lets her know he’s not into marriage. Going to the courthouse doesn’t keep couples together. Abby asks about their relationship, and Arturo says this is happiness and falling for someone.

At the church, Victoria’s surprised to see Billy arrive with Phyllis and lets him know Abby told her about what happened at Jabot. Billy feels judged, but she’s just concerned. He apologizes and assures her he’s off to rehab. She’s proud of him. Nick, Jack, and Christian arrive, and Victoria has a surprise for Nick. She warns, “He comes in peace.” Victor appears with Nikki. Faith, Mariah, and Summer are next through the door. Summer speaks to Nick alone and assures him she won’t stop the wedding. Elsewhere, Billy and Phyllis snark about the Newmans. Phyllis vows to be nice to Victor for Nick’s sake. Summer joins them and Billy apologizes for his recent drunk behavior. By the altar, Mariah updates Nick that Sharon stayed behind to center herself. At the door, Tessa arrives and confers with Mariah about whether the wedding will happen. Mariah worries Sharon decided too quickly and wonders why she’s not there yet. Abby and Arturo enter. Abby’s pleased Victor’s there. They greet Victor and Nikki, who snark to one another about Arturo afterward. Nearby, Phyllis assures Billy he’s everything she wants; she’ll stand by him. Billy feels the same way. Meanwhile, the minister is concerned about the bride being late. Mariah tells Jack she’ll run home since Sharon’s not answering texts.

More: Y&R video; Sharon Case behind-the-scenes

At Sharon’s house, Mariah calls out to her, but there’s no response.

At the church, while Nick unsuccessfully tries to reach Sharon, Summer muses to Tessa that something is clearly up. Tessa sneer about her penchant for drama. Victor grumbles to Nikki it’s no surprise Sharon’s not there, while Phyllis and Billy discuss the same thing. Phyllis is stunned when Billy tells her their wedding needs to happen after rehab. Phyllis realizes he’s proposing, and he confirms it. Suddenly, the church door busts open – it’s Mariah, who informs Nick she has no idea where Sharon is.

Next on The Young and the Restless:

An unexpected guest makes an appearance.