Subtlety is not heavy metal's default position; never has been - neither in its musical output or, indeed, its cover art. When UK hopefuls UFO approached Hipgnosis in 1975 for sleeve ideas for their new album it was the firm's crack design team, led by Storm Thorgerson, that came up with the initial idea. Thorgerson and co. then proceeded to absolutely throw the
In the UK it was released as the band intended. Sexual politics aside, it's a non gender specific couple seemingly getting it on in the bath. But the Americans wouldn't stand for such shenanigans. On its initial release in the US the offending protagonists were airbrushed out totally (with a shedload more taps added) and then subsequently replaced by the band's guitarist Michael Schenker (though not, unfortunately, in the bath).
UFO - Shoot Shoot (1975)