I get to see scenes like this all the time at 24 Kaikan (24会館) one of the largest gay baths & (love) hotels in Shinjuku Ni-chome (gay district). The bunkbed rooms are never completely dark and you can watch several guys having sex in different parts of the three rooms on the 4th floor. Sometimes it gets pretty loud when several couples are fucking noisily - with moans and groans - all going on at the same time.
Of course, I never hesitate to put by cock up a nice ass when it's offered, or have been known to offer my own to a rubberized hard little beauty of a prick. Just watching those smoooth bubble-butts rutting like a jackhammer often is enough to put me over the edge.