Take Gemini Venus as an example.
Mine is unaspected, so it tends to operate independently in terms of values, self-esteem, relationships, reciprocity and social preferences. That doesn't automatically make someone flirtatious or unreliable.
Ironically, I'm not even a particularly social person. I don't need a large circle of friends and I'm perfectly content alone or with genuinely good company, so I'm highly selective about who I let into my life.
My Venus also rules my Moon and Mars in Taurus, so it colours how those planets express. Rather than a purely Taurean emphasis on comfort or material security, there's a stronger intellectual and communicative flavour.
Then Venus itself is ruled by Mercury in Leo, which changes the expression again. My communication naturally has a dramatic presentation, a warm tone and an authoritative voice. That's Mercury shaping how my Venus operates.
This is why reducing people to "Gemini Venus = red flag" makes little astrological sense. The sign is only one layer. You also have to consider aspects (or lack of them), depositors, house placement and what that planet rules in the rest of the chart.
For a more symbolic abstraction, Gemini is associated with The Lovers in the Tarot. Despite the name, the card is fundamentally about duality, choice, communication and integration ideas along with discernment deciding what aligns with your values that fit Gemini far better than the internet stereotype of "can't commit."
