A pair of jeans with the leg holes sewn together, i.e. where the legs form one continuous tube, is topologically equivalent to a normal, unmolested pair of jeans. You can't trust topologists.
Normal jeans are homotopic to a cylinder with a point removed. Leg-sewn jeans are homotopic to a torus with a point removed. Both of these can be deformation retracted to a wedge of two circles (roughly: widen the puncture as far as you can).
I miss topology.