I know you said there's no negotiation with your wife but I would need to know exactly what she doesn't like the thought of. That would be a bit of a cop out answer to me if my oh said the same. A compromise is needed here as and I don't mean go ahead with the other woman. You need to talk with your wife again as this could so easily be resolved either with your wife and finding out her fears and reassuring her about them or using a fleshlight.
If you'd even consider cheating on your wife for something the sake of curiosity, I'd say you have a deeper problem here. I hate giving blowjobs, but my boyfriend doesn't care. I've asked him plenty of times what he thinks about it, but he's aware that I'm uncomfortable with them and he respects that, so wouldn't risk my feelings for the sake of an orgasm he can get in a way we both enjoy. Sounds like you're focusing too much on your urges and disregarding your poor wife's feelings, even though it sounds like until now you've had a good relationship for most of your life. Please talk to your wife about why she doesn't like the idea of them, and respect her answers, instead of trying to downplay them to make her do something she's uneasy about.