I (25M) am in the early days of full-time chastity where my Gf has been my keyholder for a couple days and I kept myself in check for around 5 days prior to handing my keys over to her.

A big part of why I want this is for the benefits to our relationship that stems from only being able to derive sexual pleasure from her. However, I have found that essentially every night before I fall asleep I've been reading erotic fiction or sometimes watching porn and basically using my chastity cage as a really shitty pocket pussy. I do this either on my back and tugging up on it allowing for my dick to move forward and backwards in the cage by a little less than an inch. Or by laying on my stomach and grinding my dick into the cage\sort of hump my mattress (I'm pretty sure this can cause ED problems but I'm not a doctor and when I haven't cum in a week I'm not really thinking about that).

I never allow myself to cum as I feel like that would defeat the purpose of chastity entirely. Not that I've ever gotten so close that I actually needed to stop however I have gotten into a groove a few times where I know that if I kept going that exact same way for long enough I would eventually cum.

Does anyone else do this? and would it be considered cheating my chastity or at least counterproductive to what I'm trying to accomplish?

Side note:

I'm not sure but I think my ability to do this might have something to do with the cage being to large (or I'm too small 😉) so I ordered a smaller nub size version of my cage that should be arriving tonight.