Sometimes when I randomly come across a girl who I might have met like once before (often I don't even remember their names), we naturally chat a bit and after a few minutes eventually most of them tell me to come over to their place whenever just to hang out. My question is, should I brush off these requests as them being friendly/polite and not really meaning it or should I actually take up on their offer sometime? If so, how do I ask to come over to their place when the time comes?