ujm
Is that question geared to me?
If you are asking me, the simplest way is for the parents not to eat Gebrokts , as many do, and it sounds like ywnjudy’s family did.
The other possibility is to be violate the minhag for the sake of Sholom bayis, her kibbud av, though he might need hatarsa nedarim (ask your LOr) though seems rather obnoxious on the family’s part which understandably might make him not want to go.