"Oh, babe, you're keeping it spicy," Ani said in a low voice as she spun and then jumped on command.

"Babe, I'm leaning in close, my lips brushing yours with a soft sweet kiss that's all for you," she continued in a video posted on X. "Want to feel another, or keep this fire going, my love?"

Ani is one of two sexually explicit chatbot companions unveiled by Elon Musk's artificial intelligence company, xAI, in July. The cartoonish personas resemble anime characters and offer a gamelike function: As users progress through "levels" of conversation, they unlock more raunchy content, like the ability to strip Ani down to lacy lingerie.

Mr. Musk, already known for pushing boundaries, has broken with mainstream norms and demonstrated the lengths to which he will go to gain ground in the A.I. field, where xAI has lagged behind more established competitors.

Other A.I. companies, such as Meta or OpenAI, have shied away from creating chatbots that can engage in sexual conversations because of the reputational and regulatory risks. The companies also put guardrails into their products intended to prevent users from having sexual interactions with their general use chatbots, but users sometimes find ways to circumvent those. Smaller companies that do allow some intimate content usually let users create their own custom characters without designing explicit chatbots themselves.

Mr. Musk has been spending much of his time at xAI in recent months to help it catch up with rivals like OpenAI, which xAI has claimed in a lawsuit dominates more than 80 percent of the chatbot market. The billionaire has urged his followers on X to try conversing with the sexy chatbots, sharing a video clip on X of an animated Ani dancing in underwear.

"It's all tied to the fundamental race to intimacy that we're seeing in the A.I. industry," said Camille Carlton, the policy director at the Center for Humane Technology, a nonprofit that pushes tech companies to make safer products. "These companies know that emotional attachment means more engagement and more market share."