Hahaha. Your girlfriend is so funny. Imagine having the thought of dressing to kill. Hahaha. This is the assumption of some ladies too, not knowing that the way they dress is how they would be addressed. When you dress decently, there will be that self respect in you plus having confident that even if any employer wants to try shit, you will have your stance. Dressing is something important when going for an interview. Most interviewer looks at dressing first and when you now have your skills, it's a double win for you.