Smells are a very personal thing - I've been on camera when I thought - "Fuck, who stepped on the bloated rat". It's almost always different when you are standing just a few feet away and trying to hold a camera steady than when you are actually in the "action". For me at least, the normal smells of sex are OK as long as I'm aroused - if I'm not aroused, I'm usually looking for that bloated rat.