Is his man - Idioms by The Free Dictionary
be (one's) man/woman (redirected from is his man)
be (one's) man/woman
To be adept in a particular area and thus able to be helpful or useful to someone else. If you need help with math, Todd's your man—he got an A on the last test.
be somebody’s ˈman/ˈwoman be the best person to do a particular job, etc: If you need a driver, then I’m your man. ♢ If you need a good music teacher, she’s your woman.