Your feelings and opinions".
However it seems that there is something wrong with this sentence:
“ Your feelings and opinions don’t matter when it comes to us what actually happen at the party”
A more natural sounding version could read:
“ Your feelings and opinions don’t matter to us when it comes to what actually happens at the party”
Happen is not the correct verb form; the verb must agree with its subject (what). If you want it to be a present tense verb, it must have the 3rd person S (happens).