Twitch, Amazon's livestreaming platform, is primarily a service focused on letting audiences watch others play video games. In recent months, livestreams featuring bikini-clad people in hot tubs gained a lot of attention causing some controversy.

It sounds bizarre, but it's become a thing. Hot tub streams are growing in popularity as people -- primarily women -- spend hours talking with viewers while wearing a bikini in an inflatable hot tub. It's also become a controversial topic within the Twitch community, and the company decided on Friday to create a new Pools, Hot Tubs and Beaches category just for those streamers.

It's a bold move by Twitch, which has strict policies when it comes to attire it perceives as sexualized. In a sense, it's a move that recognized -- and legitimized -- hot tub streamers.

The new Twitch category is significant on a couple of fronts, said Doron Nir, co-founder of StreamElements, which provides livestreaming tools and services.

"Because beach, pool, and hot tub streams have achieved a level of notoriety, giving them their own space instead of resorting to banning them altogether shows [Twitch is] listening to a fair amount of users who have embraced this content," said Nir. "It also signals that there will be a lot more variety on the horizon, given the willingness to support content that goes far beyond the gaming parameters of the platform's earlier days."

So what is a hot tub stream and why have they been so controversial? We have answers for you.

Hot tub stream? What's that?

It's when a person streams on Twitch while in a hot tub. Most are women in bikinis who sit in an inflatable personal hot tub while chatting with their viewers, but a few guys have also joined the trend (and some will even wear a bikini).

Why did Twitch make a hot tub category?

As with many changes in tech, it comes down to money.

In recent months, there was a growing awareness of the increasing number of hot tub streams. This was referred to in the community as the "hot tub meta," the idea being that an attractive woman can put on a bikini, sit in an inflatable hot tub and proceed to get more viewers and donations.

The community's problem with hot tub meta is related to advertising. Until last week, most hot tub streams would have been in the Just Chatting category. Some non-hot tub streamers were concerned that brands might pull their ad dollars from Just Chatting to avoid being associated with livestreams of scantily clad women. This could impact the revenues of all hosts in that category.

Twitch was aware of the concern, hence its decision to create a separate category.

Twitch hot tub streams explained: Bikinis, otters and controversy

"Today brands can target or avoid specific categories of content and flag channels that don't meet their standards," Twitch said Friday. "We think it's important that viewers have choice in determining the type of content that is suggested to them, and brands have the right to determine where their ads appear on the service."

Doesn't this go against Twitch guidelines?

Not anymore. Twitch constantly updates its policies regarding content. Back in 2016, the platform made it official that streamers didn't have to stream gaming content, allowing hosts to just sit and talk to their viewers. Now the Just Chatting category is one of the most popular on Twitch, with hundreds of thousands of people watching others talk.

There's also controversy regarding certain attire. Bikinis are OK under Twitch's nudity and attire policy as long as they cover the genitals and nipples. The streamer also can't wear anything sheer, and can't have the camera focus on body parts.

"While we have guidelines about sexually suggestive content, being found to be sexy by others is not against our rules," Twitch said in a statement Friday. "Twitch will not take enforcement action against women, or anyone on our service, for their perceived attractiveness."

Why would anyone do a hot tub stream?

We can't know everyone's motivations, but Twitch lets people find their own way to connect to a community. Some of the most popular Twitch streamers connect by playing games for several hours a day for the entertainment of their audience, all while fully clothed. Others simply live their lives, whether it's streaming as they walk around their cities in the IRL category, lift weights over in the Health & Fitness category, or just practice on the piano in the Music category.

There's the conventional reasoning that a woman could get more viewers, and in turn more donations, by wearing a bikini during a stream. In the case of Twitch streamers RayRachel and Intraventus, they said in interviews that their reasoning was simple: Their backs hurt.

"My first hot tub stream was actually last year," said Intraventus. "I have back problems and I was like, Yo, maybe this hot tub will help me out a little bit, and I was like, What if I just do a stream from the hot tub?"

RayRachel, whose streams consist of body painting that can take several hours to do, also felt some pain in her back after multiple sessions.

"So for me, it was more of an in-between-paints way to relax and have a little bit of downtime when you really don't have downtime," she said.

For them, these streams are not about having guys ogle their bodies but are a chance to relax with their viewers and create more of a community.

Not every stream in the new category even features people. The Marine Mammal Rescue channel attracts thousands of viewers who spend hours watching otters play and swim in the water.

Who has a problem with hot tub streamers?

The hate for hot tub streamers comes from all directions. As mentioned earlier, other Twitch hosts have a problem due to concerns that companies may not want to spend their ad revenue on parts of the platform that promote women in bikinis.

Other female streamers have also voiced concerns about getting unwanted social pressure from their viewers to do a hot tub stream.

Then, of course, there's the swath of users who take issue with hot tub streams either because the hosts tend to be women -- and women are frequent victims of harassment on the platform -- or because the users feel like streaming without video games goes against the "spirit" of Twitch, which was initially designed for livestreaming video games.

Félix "xQc" Lengyel, one of the most popular streamers on Twitch, tweeted some harsh words about the hot tub meta last month.

"Im gonna be honest, this hot tub meta is by far the most pathetic thing we've seen on Twitch in forever," he tweeted. "What a sad reality. Please get this trash off the frontpage."

Both RayRachel and Intraventus have dealt with their share of harassers on Twitch since their first day of streaming. Twitch making Pools, Hot Tubs and Beaches a category could help quell the harassment from users who still have issues with hot tub streamers. Or not.

"I think it's a great idea but easier to target for harassment," RayRachel said. "I think if they [Twitch] are wanting to keep it its own category, it should be monitored a lot more closely."