When a straight male attempts to appeal in a platonic way to another straight male, such as when a man tries to "bond" or be "bros" with another man. Can be used as a manipulative tool, or is just used by an overly friendly male. Also a noun.
"Ever since Jimmy decided to be in a frat, he totally man-flirts with every member!"
"My father is such a man-flirt with my boyfriend, he wants to bond with him so badly."