Hi anon, great question.
The first thing is to talk about it, more. I know you do. But you can’t hear enough him saying ‘it’s okay’.
But here’s the next level that I think will help to. For him to say ‘I want you to safeword’ and you both begin an activity where the actual objective is to get you to do it.
Well with denial it’s usually quite easy. Either using the gentler approach of edging you until you safeword out, or, more quickly, using post orgasm torture (POT) until you do it.
http://edging.space/tagged/pot/chrono – you may regret your dom ever reading that, just FYI…
This POT is especially effective, and beginning a scene with him saying something like, ‘So, after I make you cum, or if I’m feeling mean, ruining you, I’m going to put this vibe/my fingers/mouth back on you and torture your clit until you scream ‘Red’ babygirl – just so you learn it’s okay to use it and I’m always happy if you do. I will never be cross with you for safewording, and you need to learn that, okay?’
If you do that a few times, knowing he actually wants you to do it, and learning it’s safe and okay to use your safewords, then it gets you past the misconception that they are something bad and disappointing.
A good dom WANTS to know you’ll use a safeword when you need to, it’s part of an important safety protocol that makes sure we’re looking after you. If that part of it isn’t working then we’re skating on thin ice.
As such, if I’m helping someone new and taking them into areas where safewords are of use then when I check with them what we’re using (red and yellow are my preference) I’ll also tell them I plan to deliberately see if they’ll use them when they should. Even this changes the dynamic as you’re always thinking ‘Oh maybe he’s testing if I should safeword now, so that’s okay, I’ll use it).
And at some point soon after that I will push them hard, ideally getting them to a ‘yellow’ point they say themselves, and if they don’t, I’ll stop things and ask why not and we’ll discuss them again. It’s all part of getting them used to the fact that a safeword is NOT a failure of any kind, it’s a direct form of communication that’s vital in Ds play to make sure it’s safe, sane and consensual.
I hope that some of the above tips will help you feel that too.