this is about a father celebrating his daughter's wedding. Don't make it about you. Try to support your partner as he supports his daughter on her big day. Keep your own ego out of it.

However, no need to be a hypocrite. The way they have made it clear you are not family relieves you of the burden of pretense.

You don't need to act all warm and loving when, at some later date, they agree to meet you. Just stay civil and let them set the tone.