Just a thought. My wife's agreed (finally!) that 3 bikes is OK:
- Main road bike
- Mountain bike
- Winter road bike/backup
Only I've got 4, including the 'loan bike' - a freebie road bike.
My wife may have many faults but she understands my hobby keeps me sane (ish 0 and drew the line at 3 bikes as well....
1.The niceroad bike
2.The commuter/winter roadbike
3.The rigid MTB commuter
Its the endless supply of spares that adds up though , i must have at least 3 sets of spare tyres and a good 10 + inner tubes not to mention spare cassettes,chains, brakes pads and odds and sods.
back to the OP you need a minimum of 2 in case 1 breaks down so you can still ride , ask your other half if she could live with just one pair of shoes ?