“sus” Text Meaning

Suspicious. From gaming slang — something does not add up.

Guys rarely encrypt slang. "sus" from him means what it means everywhere — but note whether his slang loosens up with you specifically, because comfort and informality with one person is its own signal.

From a girl, "sus" is also mostly literal — but girls more often use slang to set tone: playful, casual, unbothered. If her slang level with you is different from her formal style elsewhere, she is choosing the register she wants with you.

Match the energy and keep the exchange moving. Slang is casual by design, so a casual, quick reply fits better than a formal one.