"有纨绔习气的" can be translated into English as "having the airs or habits of a playboy/dandy" or more naturally as "possessing a frivolous or spoiled playboy-like demeanor".
Here are a few variations depending on context:
He has a playboy/dandyish demeanor.
He exhibits the habits of a frivolous, spoiled young man.
He carries an air of entitlement typical of a wealthy, idle youth.
The most concise and contextually appropriate choice might be: