I think the sex battles are too simple, too easy. Press 4 buttons over and over again, cum, rinse repeat til the enemy is satisfied. No cost, no losses, except maybe -4 hp from the starting encounter

As well as the fact that these sex battles are unrealistic. A goblin penis might slip in pretty easy dry, albeit a little painful. A giants penis is gonna need buckets of lube for that cock anywhere. (Thats a lot of damage)

Adding a mechanic where you have to continually stock up on lube, cause your sorry ass is gonna need it, would fit perfectly into the game already. You already take damage from the giant anyways, make it do more/less if its dry/lubed. The slime gives you mysterious goo, theirs dry anal with the brigand.

Maybe the mysterious go could make dicks like the giants or other crazy cocks not do damage

Maybe do damage with no lube for anybody, cock size corresponds with amount of damage

Idk about a whole new system just to force the player to complete mundane shopping lists for lube after every excursion.

But you're right that sex and battle is too easy. Being on the receiving end of submissive sex could include damage, or getting pumped too full (ettin) could be small damage over time. Good ideas. A better fit for developers would be to change enemy AI so that they try to dominate you and keep you pinned down or impaled on their cock until you submit or faint.