The 24-year-old actress - who plays Rachel Berry in the musical TV series - explained while she can understand why people think the cast are dating one another, she thinks if any of her co-stars were in a relationship it would create "awkward tension" on the set of the show.
She explained: "Everyone thinks that everyone is sleeping with everyone. We spend every minute of every day together, and when we're finished, we all go out to dinner, so of course, they think we're hooking up.
"I'm so thankful that doesn't happen. If people hooked up, there'd be awkward tension."
While Lea enjoys hanging out with her fellow cast members, when she has free time on her hands she loves going on virtual dates with her boyfriend - Broadway star Theo Stockman - over internet phone service Skype
She added to Cosmopolitan magazine: "Take a shower, put on a robe, pour myself a glass of wine, and Skype with Theo. That's the best."