I bought my GF a new seat for her bike, one of those wide versions
that fits a lady's pelvis a bit better than the OEM man's style. I
put it on for her while she was in class, just before we were to go
riding with a friend of ours. She came out to get her bike, and
didn't at first realise the seat had been changed, but then the
odor of new leather came to her, and she realized what I had done.
We rode to Barry's house, picked him up and started riding down the
valley route. She was a bit proud of the seat, so she told Barry I
had gotten it, and that she hadn't caught on til she smelled the
difference. And Barry quipped:
"You mean you smell bicycle seats??"