I had a roommate back in college (early 1960s) who wore his calfskin opera pumps with jeans. He was from old money and didn't give a crap about what the other guys thought. He was from old money and the girls didn't seem to mind a bit.
Opera Pumps - What's the Deal? - Page 7
I would never wear them but........ http://barimavox.blogspot.ie/2010/08/black-tie-decolletage.html
Before I was married I had a group of single female friends who used me as their +1 to charity gigs, etc because they knew I knew which fork to use and they wouldn't have to fight me off at the end of the night.
Went through a couple tuxedos and a single pair of Bally calf opera pumps that wore like iron and felt like buttah!!
I like the way they look and the chances are/were that, even at a so-called formal event I'd be the only guy there wearing them.
The only other men were usually older...MUCH older.
Actually, men's opera pumps are only worn with White Tie and Tails. This is the most formal and classic of men's attire. They are never worn with a tuxedo. A tuxedo is considered a less formal. It was originally worn by the Duke of Windsor when he asked his tailor to create a shorter jacket for less formal dinners. With a tuxedo you can wear any type of dressier black shoe including patent leather and they can be tie or slip on, (sometimes referred to as a slipper).
Most formal events in the U.S. are "black tie" and therefore call for a tuxedo or a dinner jacket, also called an evening jacket. To a black tie event, one can either wear a full tuxedo where the jacket and pants match like a suit, in black or other appropriate colors, (including navy blue) or a different evening jacket made of several different material such as wool, silk, or velvet in an array of colors.
One would wear tails only to a "white tie" event, which is more rare these days and almost non-existent in the U.S. To a white tie event, one would only ever where a tailcoat and matching pants,(in black) a white shirt with a wing collar, white or off white evening waistcoat (vest) made of cotton pique fabric, a white or off white (matching the waistcoat) bow tie also made of cotton pique and yes black opera pumps with a grosgrain bow. This is the only time such a shoe would be worn. If you were hosting the white tie event in your home then black velvet "slippers" (meaning a slip on shoe in velvet) could be worn, but only by the host. Tuxedos or other attire would not be appropriate for a white tie.
In the later part of the 19th century and early part of the 20th century, white tie and tails were the standard evening attire for men until the "Tuxedo" was coined at the Tuxedo Club in Tuxedo Park, NY when wealthy business men began wearing a coat similar to the one commissioned by the duke of Windsor. Brooks Brothers actually sells the white tie ensemble including the pumps.