AC wiring question

[metallitera]

ok, i need you electricians out there to help me out.

i have a 240VAC outlet on my generator that i was gonna use to run to my trailer and the split it to two 120VAC legs since it can handle more amps. that seems easy to me. the 2 legs share the ground and neutral wire and they each have their own hot wire.

now my question. the plug used above is a 4 prong twist lock, and i wanna be able to hook into the house power when able to, so I was gonna get a FEMALE 240VAC 4 prong twist lock and run that to TWO 120VAC "regular" plugs. again i'd have to combine the grounds and neutrals, and then each hot wire would go to its own leg. will i run into problems connecting the 2 grounds and neutrals of the household plugs?