Possible Clues:

• Not being nasty to one sticking nose in
• Uses old or new type of method to defeat sniffer-dogs
• Unscented variety of rose sold outside university
• Like certain gases, not sensible to sniff
• Lacking smell
• Grim fellow visiting one-time sweetheart initially without bouquet
• Impossible to detect by olfaction
• Morose fellow in old store initially lacking scent
• I left serious old building without perfume
• Lacking fragrance, love? Manufacture or use LSD