Unsure whether he's just being polite or flirting? This flirting expert says these are the signs to look for.
1. Humour
Are they trying to target you with their jokes, trying to create a shared space between you? If so, it's a very good sign.
2. Body language
Positive signals are if they are squared up, facing you, with their feet pointed in your direction. The feet are a helpful guide — if they are angled towards you, it shows the person is into your conversation. Angled away? Chances are they are planning a quick getaway. Similarly, if they have their arms crossed, they're not really into it.