Unfortunately the place I found it had no information about the manga or the artist whatsoever. It just had a caption underneath it that said something like "The guy that's just passed her is sweating.
". So yeah, not helpful.
If it helps:
http://www.heavychests.com/WARNING!! THERE BE BOOBS IN THERE! BIIIIIIIIIIIIG ONES!
Anyway, it's the second picture down. Hard to miss.