The mugstache (more commonly known as mustache cup) is a popular type of mug from the 1860 – 1916 among British soldiers.
This is because the soldiers at that time were required to keep a mustache as it is associated with virility and aggression. Due to this, the soldiers used wax and dye to groom it. However, when they drink a hot cup of coffee or tea, the dye and the wax will melt and flow into the mug which is how this mugstache was popularized. The mug was invented somewhere between 1850 and 1860.
Spoontache (more commonly known as mustache spoon) was also a thing for them to drink soup. But unlike mugstache, spoontache has been discontinued.