Dating rumors have been one of the most common triggers among issues between SM Entertainment and its stars. As KpopStarz noted, it is unclear why SM is approving some of its stars' relationship and not the others

Sungmin of Super Junior reportedly came clean with dating a musical actress while Girls' Generation's Taeyeon, Sooyoung, YoonA, Tiffany, Hyoyeon, and Jessica have either confirmed relationships or have been rumored to be dating, the website noted.

One of the most talked about dating rumors is that of Taeyeon and EXO's Baekhyun. AllKpop reported that SM confirmed the rumors, with a representative saying, "Having started off as close sunbae-hoobae, the two recently developed feeling for each other and are in the beginning stages."

After the confirmation, fans of idols reacted negatively, causing the two to apologize to them several times. During the time, Baekhyun was part of the musical, "Singin' in the Rain." When the news came out, ticket sales went down immediately after their relationship was publicized.

On the other hand, the agency denied dating rumors involving f(x) members Luna and Sulli. After months of denying the issues concerning the latter, SM finally confirmed Sulli's relationship with Dynamic Duo's Choiza. This was followed by announcement that Sulli will be taking an indefinite hiatus. This took place in the middles of f(x)'s promotion of "Red Light," causing several speculations and with fans outraged by the news.

As KpopStars noted, the difference in handling star's dating rumors is based on the group's longevity. According to the website, dating news might take a toll on a group's popularity.

Compared to SM's younger groups, Super Junior and Girls' Generation have continued success due to their fairly established name in the industry. While the two groups were involved in several issues, members of their strong fanbase still support them, giving them to continue releasing hit after hit.

As mentioned by KpopStars, neither of the two groups risk their professional careers by dating. "The individual members are popular enough, and have enough solo activities, that even if one member gets brought down, the entire group will not inevitably suffer. The differentiation between being members of an idol group and being individual entertainers is what is important," said the website.

"SM Entertainment is becoming much more open to its idols dating, easily confirming relationships when the groups are not at risk," added the website.

Meanwhile, earlier this year, "Miss Korea" star Lee Yeon Hee revealed something about the agency's dating policy saying she is not happy with the rules. "They tell us that dating is allowed but that we shouldn't be discovered."