Bokuman hasn’t specifically labeled this as breast expansion, but it seems pretty obvious to me. We’ve got a healthy but lissome nurse who suddenly has buttons popping off into space, with enormous breasts bursting forth as the blouse gives way? Either she was dressing in clothes that were way too tight for her generous bosom, or she’s just experiencing some radical expansion while at work. I’m going with the first explanation, so now we just have to imagine a set of circumstances (some kind of medical accident, obviously), that’s caused this formerly ordinary young woman to grow the biggest tits in town!

She certainly does look surprised!

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