To complain irritatingly about a future event that may or may not happen.
For example,If we go there, the Sox will lose, you'll get drunk and I'll hate it.
If we have that picnic, it'll be 90 degrees, we'll be attacked by wasps and I'll hate it.
If you buy that, it will wear out, we'll go broke and I'll hate it.

A tourist to sub-orbital or orbital space, through commercial space flight programs.

To complain about something long before it happens.

(inf) uses: prebitching, prebitch, prebitched. To complain about a device or service when the device is announced but long before it is actually released. Seen in the gadget world frequently when devices' functions are announced but a prototype or working model is still a year away.
Any announcement on a blog of a new device will be followed by a wave of commentary prebitching about said device. Common examples will start with, "I haven't held this product in my hands, but right off the bat..."