Probably a bit of a novice query...

I’ve been testing out a few different cages over the last couple of months. My partner enjoys keeping me locked up until she makes her final decision. I’ve found one that fits well and is comfortable, but there’s still an issue. It seems I’m what you’d call a ‘grower,’ particularly during the night or early morning when I wake up with an erection. The problem isn’t that the erection doesn’t happen; it just occurs right in front of the ring instead of inside. Since my penis can’t expand much, it pushes forward against the cage opening. For sleeping, I need straps that are easy to adjust and keep the device snug against me so everything stays put rather than sliding down. I’ve looked around but haven’t found anything quite right yet. Ideally, I want something with little give that holds the cage firmly in position. I’ve tried some harnesses before, but they aren’t really designed for this specific purpose. Does anyone know of a simple yet effective solution to prevent erections from pushing out against the front? My ring size is fine; trying smaller rings hasn’t worked because it causes too much pain and doesn’t stop the forward movement. Any suggestions? DIY options or tips on where to find suitable gear? Thanks!