How can you tell the difference between a joke and flirting?

Anonymous
How can you tell the difference between a guy who is just joking with you generally flirting and is into you. I know a guy who has said many things to me but I never actually know if he means any of it, he helped me recently at work and I bought him a coffee as a thank you, I left it in my female work colleagues office, she passed on the message there was something in there from me and his reply to her was “is it her number” he’s also said other things to me like … he mentioned there was a discount for our staff members at a local supermarket, I told him that I didn’t know this and he said “ I should of called you” even though he doesn’t have my number, also sometimes we bump into each other at a local store, he also said to me recently that when he goes there he looks out for me? I really like this guy but I’m confused as to if he’s just kidding with me or if he’s actually interested … I’m not sure if I should give him my number or At least offer this to him?
How can you tell the difference between a joke and flirting?
2 Opinion