Novices and newbies discussion

Greetings all, I’ve recently acquired a chastity tube, but I’m facing an issue with a potential girlfriend (who is still in the testing phase). The lady I hope to be with is significantly older than me and isn’t particularly keen on the concept of being kept. To be honest, I am still a virgin and would like her to have the say-so regarding whether I get to enjoy sex or not. We do engage in oral Sex (giving cunnilingus), and we both really enjoy it. So here is my question: How can I spark her interest in chastity? I introduced this Forum to her so she could see the perks of keeping a man locked up. And a huge thank you to margarett for your help.