If someone is sending you mixed signals, what do you do?

Remember back to a time you have sent someone mixed signals, what was their reaction?

EDIT: When I refer to mixed signals, I mean, both body language and what is said sometimes suggest that they are interested, but sometimes… they seem unsure themselves. And to top it off, let’s also assume they are a good friend of yours.

And what would you do if you were on the other end?