Dp and I have been having a "discussion"
In the interests of fairness this discussion stems from a work colleague asking me to his hotel for a quick dinner after work (expenses). This colleauge is married, and probably at least 25 years older than me. He thought I was single. Dp thinks he is "after me" I disagree but hey ho.
Anyhow. I say that it's perfectly acceptable to go out for lunch/coffee with a friend/ work colleague no matter their age/sex/sexual orientation whatever.. If you are in a relationship then you have trust. It shouldn't matter who it is.
Dp reckons whilst its fine to have girl friends, and go out with female work mates, should it be a hetro male then this crosses a line, and isn't acceptable...
He suggested MN as the voice of reason, and reckons "I'll be surprised at the outcome".. I laughed. 
So what do you think?