Is it actually a main fuse or worse?

[atomic01]

Long time reader, first time poster ...

I have a 2007 GZ250. A few weeks back, I was riding it every day to work with absolutely zero issues. One night I rode over to a buddy's house and let him and another friend (both motorcycle riders) drive my bike 2 blocks up the street and back. Once again, zero issues. We parked the bike to go inside and check on the burgers. We came out 10 minutes later to see who's bike had the best high beams. Problems began ...

The GZ would NOT start. No clicking, no nothing. The checklist: plenty of gas, plenty of battery life, kickstand up and all the other stuff people forget sometimes. We DID however get the bike to push start. The engine sounded like a machine gun going off, highlight barely lit, and when I tried putting it into first it would just lurch a few times and die.

Any ideas? The more I read, the more I think it could be the main fuse and I can certainly replace the fuses. CDI? Starter relay? If it was the main fuse, how did we get it push started?

Any help would be more valuable than you know! Thanks in advance.