The list of biological processes that rely on nitric oxide (NO) continues to grow – it is involved in muscle relaxation, the immune response, memory and, of course, sexual arousal and plenty more besides. Ever since that discovery, if not before, I suppose you could say that saying NO has become a prerequisite for sex. Although for legal reasons we should disassociate ourselves from such a puerile, or should that be penile, comment. For more chemical fun and games, check out Paul May’s silly molecules page at Bristol University where you will find arsoles, cummingtonite, and spermine. Over on ChemSpider.com you will find similarly puerile behaviour in the form of coxafloppin, mycoxadroopin, and more.