PC is peer to peer support and that is made crystal clear when you sign up for an account.
I’m sorry your not hearing what you want to hear but you are cheating on a person you say you love. You don’t cheat and trip over yourself trying to justify it.. whether you cheated once or 20 times or 163 ... you are still a cheater.
You need a professional to help you sort your skewed thinking apart.
Either love her and her alone or just be single and indulges any fantasy you want.
She deserves to know.. not all STD’s can be cured..I pray she won’t have to pay for your unfaithfulness the rest of her life.