Lena opposes the singer's alleged reconciliation with the bad boy rapper and says it saddens her to think they've reunited.
"She left Barbados, she's had this amazing career, she's won a Grammy... She's talented. And then she gets back together with Chris Brown and posts a million pictures of them smoking marijuana together on a bed," Lena ranted. "And it cracks my heart in half in a way that makes me feel like I'm 95 years old."
The outspoken comedienne discussed the influence celebrities can have on their fans. The Golden Globe Award winner believes that stars have a certain amount of responsibility to set a good example to their followers.
"It's an amazing thing and it's like, it's a platform that you have to take seriously," Lena continued.
"Which is why sometimes it's like I used to be really into Rihanna, that pop star, and then it's like again, I don't want to ever throw stones from my glass house, but I follow her on Instagram and I just think about how many little girls beyond what I could even comprehend are obsessed with Rihanna."
This isn't the first time the American star has spoken about her objections to Rihanna's reunion with Chris, which comes three years after they famously split following a domestic abuse incident. Last February Lena remarked on the controversial couple's restored relationship on Twitter.
"Rihanna and Chris Brown's new duets make me want to go hide under Gloria Steinem's bed for 72 hours," she tweeted.