ever been in the situation where you're talking to someone about something which is not meant to be funny

not meant to be serious either, but they start giggling or even burst out laughing? this has happened a few times, once with some young woman i was talking to about something, and as i was putting a point of view over to her, she suddenly starting giggling, and i felt a bit uptight about that and said ' hang on, how is that funny? i didn't see the funny side ' as what i was telling her wasn't meant to be funny?

anyone ever have a situation like this?