Had mine sucked by the hubby when joining couples. Not really bothered but went along with it as they enjoyed it and it's still kinda hot. With their wife straddling my face at least 😂😉
Honestly, I don't think it does anything for Mrs either way - she enjoys seeing me have fun, and it's become a relatively normal part of our threesomes (we lean toward bi guys), but I don't think it necessarily turns her on