There is, of course, always the potential for conflict between these two signs. (This is a good time to mention that you really do need both people's entire birth charts to get a full sense of their compatibility!)
For instance, Gemini is built for intellectualizing, trying everything they can, and being self-sufficient. Leo appreciates attention and affection, so it's possible they may feel slighted when Gemini's attention is elsewhere, according to Pennington.
"I wouldn't want Leo to feel like they weren't being paid attention to, but something like that could potentially arise," she tells mbg, adding, "And then on the other side, Gemini could feel that what they're up to is so awesome, so why is Leo always getting all of the praise and attention?"
Leo is also very concerned with loyalty, and no Gemini slander here, but "loyalty" doesn't always hold the same importance to them—or at least, they don't think about loyalty in the same way. Not to say they're inherently disloyal, but Geminis tend to have more scattered attention spans. This can disrupt Leo's need for recognition.
If these two signs were at a party together, for example, Gemini would likely be the one bouncing around the room having tons of stimulating conversations with a variety of people. Meanwhile, Leo would probably be entertaining a circle of people with a performative monologue or story, wondering where Gemini ran off to.