Mixed-sex friendships and marital trouble

Mixed-sex friendships and marital trouble
Jeff Culbreath, a frequent commentator on this blog who was born in the same city as my parents, had some things to say about mixed-sex friendships in comments attached to a previous post. He doesn’t think they’re a good idea in general, saying that they can “take an inappropriate turn” and they “makes for really wimpy and effeminate men.” I always respect his intelligent comments, but I respectfully disagree.
Intra-sexual friendships are most likely to take the wrong road if you’re in the wrong setting. When I say I’m friends with females I work with, I mean that I talk to them on a personal level, and if they happen to be at a work-related gathering I won’t run away screaming. I wouldn’t go out to dinner with them at a cozy restaurant. I wouldn’t go out one-on-one for drinks after work. But I will talk to them about their lives, their views on the world, and my own life and views. The kind of things friends talk about.
I can’t see anything sinful in that, nor do I think it would lead to something sordid. I would not hold myself up as the ultimate moral exemplar, but I’ve got a good marriage and a healthy family life, and I’m not afraid to talk about my faith with others. Should I refrain from giving a good, positive manifestation — or something like it — of Catholic family life? Most of my friends are Catholic, and I don’t have that much opportunity to give a personal witness of the Faith outside of work. It would be hard to do that without talking to my non-male co-workers.
For myself [clearing throat, puffing up chest], I can say having women around hasn’t made me effeminate yet. If women in the workplace makes the environment less masculine, that’s not necessarily bad. I don’t think an all-female or all-male environment is completely healthy, except in a limited number of settings. (Convents, monasteries, and schools are some of those settings.) The worst tendencies of each sex comes out when there is too much testosterone or estrogen concentrated in a small space.
Your thoughts?