Is the Ring Supposed to Hurt Like This in This Scenario?

I’m currently using a temporary ring that can be adjusted to fit tighter or looser… I read somewhere that the ideal size allows you to slip the tip of your little finger through it while wearing it. So, I tried that approach but haven’t started wearing my cuck tube yet; for now, I just have the ring on during the day. However, when my partner gets aroused and swells up more, the ring digs into me quite a bit and presses against my balls. Is this level of pain normal, or should I loosen it up? I’m wondering about what people say regarding blood flow needing to move easily… does that only apply when my penis is flaccid?

It's usually not a great idea to get into the habit of wearing just the ring, as you've found out.