Can I-130 & I-485 for derivative beneficiary (step-son) be filed before I-130 & I-485

[georgenik]

Not a "standart" situation.
I am married to american citizen for 5 years. I have a 20 y.o. unmarried son - stepson for my american wife.
We never filed I-130 and I-485 for myself (primary beneficiary) and for some reasons not going to file them in the nearest future.
Can we file i-130 & I-485 for my son (derivative beneficiary) without filing I-130 for me?

[newacct]

Not a "standart" situation.
I am married to american citizen for 5 years. I have a 20 y.o. unmarried son - stepson for my american wife.
We never filed I-130 and I-485 for myself (primary beneficiary) and for some reasons not going to file them in the nearest future.
Can we file i-130 & I-485 for my son (derivative beneficiary) without filing I-130 for me?

There are no derivative beneficiaries in the Immediate Relative category. You are your son are petitioned separately, and are both principal beneficiaries. Yes, either of you can be petitioned and immigrate without the other; your immigration processes are completely separate.