You KNOW there’s a brothel that constantly brews polyjuice. Bring in a hair from the person you’re attracted to, and have sex with (someone who looks exactly like) them!
You can even obliviate the polyjuice’d person afterwards and leave no evidence behind. Consent in the wizarding world is beyond fucked.
I should not be involved with people who turn a blind eye to fascism.
Full stop.
I’m sorry to say that you already know what you have to do. There’s no easy way to do it other than to just do it. If it makes the process easier, you don’t have to pose it as “it’s me or them” because you already know what his answer will be. If he was going to change, he’s had plenty of opportunities already.
Don’t wait for him anymore. Live YOUR life.
Also relevant - you can’t smell porn. Everyone has a scent, especially when doing a physical activity.