Right.  In the mind of a fat, any friendly or polite interaction from any male of any status is interpreted as "proof" that "the men all luv muh curvezz".  There is also the possibility that they dimly realize that they're far too repulsive for any normal, attractive man to want a relationship with, so they're making fools of themselves hoping for a one-off grubby, drunken adulterous dalliance.