I guess you could show him your passport! I'm a hybrid too, born in England to a Welsh father and a mother born in England to two Irish parents - and compounded by being married to a Scotsman (twice).
I'm like you ummmm, mum born in South Shields dad in Wigan, grandparents from Dublin, Cobh, Cork and Belfast. My two sisters and myself were born in Nottinghamshire and I'm English and proud of it.