Dudes who wear thumb rings are pretty much the worst. They are the kinds of guys who worked on the student poetry magazine in high school. These Ducky deadringers spend their time pining over a girl who is clearly out of their league and plan elaborate ways to weasel into her life. Like, he'll memorize her schedule and "magically" show up, playing it off as an eerie coincidence: "Oh, I didn't realize that you took yoga classes here every Tuesday at 5pm. What a coinkydink!" Groan.
If, God forbid, you date a thumbringer, prepare to have your entire relationship chronicled in some kind of art form. A comic, a short film, a novella, a painting; these guys must document everything that you do together. Think Dawson Leary but with even less appeal (as if that was possible!)
Thumbringers identify with all of John Cusack's movie characters and look to the stereo scene in Say Anything as the pinnacle of romantic gestures. When you try to dump him, he flat out won't let you and will insist on several drawn-out phone conversations, asking you to go into detail about why you are unsatisfied with the relationship.
Here's the reason why you had to pull the plug: he is terrible in bed and his phony sensitive guy shtick is uber-irritating. Obviously, you can't tell him that and if you did, it'd just end up as a lyric to a song he'd premiere during the next open mic night at the local cafe. Just do both of you guys a favor and give him the cold shoulder; it's for the best.