Looks like you were thinking about the complications that can occur during longterm chastity while you were doing these caps. So many variations for the women to enjoy and the chaste guys to endure. Like sending hubby as the wife's sexual surrogate to satisfy one of her many lovers. The cuckold won't get over that anytime soon.
Cuckolding is an interesting realm. To me, it follows on naturally from the woman's control of the man's orgasms, but some chastity enthusiasts apparently don't agree. The blogger who initially inspired me - ptathuk - separated his caps into two sites, the cuckold ones and the non-cuckold ones.
Also, having your key lost in a cardgame would be devastating. You might want to explore more possibilities of keys being loaned out, traded, passed around, or otherwise changing hands.
I've done a few, but the field is intrinsically a bit limited, and I try not to cover the same ground as before. I do more with the VICTIM - or his 'services' - being loaned out though ... broader field.