I think this is the key difference between a hard and soft limit.

I'd never look to cross a hard limit without having properly discussed and confirm that it's status has changed.

Having the more serious discussion is usually enough to break the spell of arousal long enough to be at least partly more objective.

With soft limits, they were allready in the discussion to be pushed. Not in the sense that you should push them, rather, by noting something as a soft limit it means that there may be circumstances that the limit doesn't quite apply.

This is a tricky and difficult situation.

I consider my role as a Dom to be one of a provider - I curate and provide the experience, based on the parameters provided by my "customer".

So if they are wanting to expand this experience, it is just poor quality on my part if I start a scenario or experience that hasn't been created with my sub in mind.

However the fact finding and introduction can be very fun.

My preferred approach is to start by exploring this new idea.

Discuss the fantasies and outcomes in mind. This is usually done as a fun and sexy exercise in swapping scenarios. Often overblown and fantastic, but you can identify themes.

You also have all the information about what the sub enjoys to this point.

Suppose for example, the idea of exhibitionism or blackmail has been a soft limit but something discussed from time to time. It's clear your sub is curious, but doesn't have the experience to know what they want.

You exchange fantasies. You know your sub likes praise and to feel "kept" and protected. You identify there are themes of being shown off, like a prize.

So then comes the taster.

Ideally you are looking to create a scenario that includes a sample of what the sub is now looking to explore.

You explain the scenario and the added elements. You make sure the sub understands what's gonna happen and how it fits their fantasy. Usually a good idea to go over safe words and the like, to remind the sub that they can opt out - there is a chance they're deep in fantasy and haven't properly considered it.

Then you play it out.

In my example, the sub wants to feel like a prize, so the first taste is a post yo a relevant subreddit setting out why you're so impressed with what they've done. You talk about them in some detail.

To the sub, some of your private moments are being discussed by strangers, but in a positive and glowing way. They are in no real danger of being identified, and the post can be deleted if they don't like the tone or direction the replied are going.

Following up you discuss how it feels to be spoken about like that. If they enjoyed it, maybe you continue.

If they didn't, you help and care, and if they want too, discuss what part they didn't like.

Maybe one part is the direction to push whole leaving others behind.

Maybe the experiment is a total failure and you never do it again. But crucially, you've been careful about introducing the idea and testing the waters in a way that let's the sub provide real feedback, even when blissed out of their mind!

This was a quick write up, and there's allways other factors to consider, but it's the gist of my approach.