bra swap

This girl from high-school, kind of an excessive tom-boy, was in the bathroom. She starts to ask me something and I appoligise to her (for what?) and give her a hug. She wants to know if she can borrow my bra... an underwire. She offers me her sports bra if I want it, it is an emergancy she says. She is considerably better endowed than myself... but the phrase "give him the shirt off your back" comes to mind... "give her the bra off your chest..." and so I do, declining her sportsbra and wearing a patterned strapless runched elastic shirt alone underneath my shirt.