When you surrender to the warlock, she gives you 3 options. One of them gives you a game over, another one makes your dick useless.

But what does the other option does? The one that makes you love dicks. I don't see any change on the quest log or the character menu, and the game seems to get no change as well.

it is an effect that can be detrimental in some events, just like "anal addict" or "manic mouth". this effect, like the others mentioned, consume willpower if you want to resist an event that can end in a "game over" (only in some cases)

All 3 scenes can be seen to their completion, you will only receive a 'game over' if you have low purity.