Sorry, folks, but your both wrong.
Melv, what you've come up against is a simple thing called "parasitic drain". It can be caused by a few things, but in this case, it's simply because the bike hasn't been run in 2 months.
What has happened is that due to both the passage of time, and the drop in temperature, the batter has lost some if it's available voltage. Typically, a fully charged battery will read 12.6V, on a warm (70 degrees Farenheit) day. When the temperature drops, that can go to as low as 12.3-12.25V, even though it may be fully charged and never have been used.
The easiest fix is to remove the battery, take it indoors (or to a wam place, at the very least) and let it warm to room temperature. Give it an open voltage test (use a multimeter...set to volts DC and place the leads..read the display) and if it's lacking, give it a charge. Once it's up to snuff, replace it in the bike, and hit the starter. That *should* cure your problem..and remember...even it's not going anywhere, start the bike up to charge the battery. It'll save you headaches like this one in the future.
Hope this helps
ZX