Can you flirt too much?

I work with 2 men that are very nice and very helpful. When we are not busy we have down time and sit around and laugh and talk. There will be statements made that make me smile from ear to ear and of course I will make comments in return. Now none of the persons involved are married or in any type of relationship so I should not feel like I am doing anything wrong and I don't believe there are any romantic interest. I feel that they joking with me but I also feel they are serious.
Maybe I am just thinking to much. I should enjoy the fun and go with.