I would caution you to have a frank and honest conversation with your wife about your desire before you go looking for someone to live out the fantasy. Starting by telling her how you like to be fellated and showing her with a dildo would be a great place to start..you could wistfully admit that you wish you could try the real thing, though you really don't want the whole homosexual sex experience just this isolated experience. Then let her know how exciting it is to think about either licking her or watching someone lick her (depending on how open your marriage is to threesomes and the like, this is a senstive issues with lots of ladies) while she was getting fucked.
If you do bring it up you might find a willing partner who can help you explore this desire and I usually find that opportunities present themselves easier and more naturally this way.
I admitted to my partners that I LOVE a nice rack on a woman...I'm not much into the other lady bits but playing with a great set of boobs is nom nom nom! It lead to a lovely experience where we played with a lady who was also very much into touching but not tasting and a very exciting threesome. So I know it can happen and lots of guys I have talked to wouldn't mind a great blowjob from another guy but don't consider themselves bi or gay.
The net has so much information about just about anything that has to do with sex and a few dozen things that most people would never connect with sex so I am sure there are plenty of places for otherwise straight guys to get their oral fix! Happy Hunting, indeed!