Re: the need to flirt
my very liberal self agrees with queer.
That being said, if you think your spouse is in your opinion flirting or someone else is flirting with him/her, do express/communicate it in a mature way. You will find out that he/she either does not consider it flirting (meaning you two have very different standards of what flirting is) or will deny it, which means you have bigger issues to deal with.
My point is, don't suffer in silence but don't be a control-freak either.