Chastity and orgasm denial discussion

my wife/keyholder wants sex often but very much enjoys the benefits of tease and denial for me. We are trying to find a penis sheath that i can slip my hard cock into and fuck her for at least 20-30 mins without cumming. We need something that is thick enough to prevent any pleasure for me because after being locked up for a week or more..i cum very easily. I found something that might work on but not sure. Anyone delt with this situation before? thank you!