Romance, whatever it is - from falling in love to sexuality and beyond, it's just part of life. Just like the other wants, food or drinks. Or wanting that cool armor, legendary weapon, magic skill, treasure, and everything else.
All these can go wrong. Not the subject is bad in itself, just how it is implemented in a game. That can go wrong.
Love is just like food, isn't good when it's forced. You have to want it first. Then have to be cooked properly, unless you that hungry, because otherwise you get sick and won't feel it as a joy. That's why there has to be a teasing first and an easy way to refuse that. Nothing wrong at this point, just take it a a compliment. You may become hungry later. Or not.
Depends on the food as well: a tasty cookie could be always tempting. It's up to those laws of attraction. These make a game more rich, even if we just react with some kind of "no". Don't have to end in a complicated a scene. Just a single line of teasing, from a character you encouraged to do so, goes deep.
So I don't think a toggle needed, as in option & settings. Just to be well written, and allow for a refusal, from a simple one, to a polite or even threatening one "don't even try this again with me", including the "maybe later" leaving the door open. These won't make a game feel cheep or creepy. They will actually add a lot, they make sense and nothing to be afraid of.
We can't just keep censoring the most important parts of our humanity; that is falling in love, from the fear of doing something weird. These parts just need a better writing than games get usually. Still, props for those trying, considering the "western" world we live in 2020 is still ashamed of sexuality and feelings, and how can one learn a proper way (of writing) without trying and failing, making corrections, trying again, doing better and in the end, getting it right. Just try it in real life, if you haven't yet, and see that "romance" it's never a 100% success story
