SHE CAN GET SOME TASTEFUL LUBRICATIONS TO USE IF THAT IS THE PROBLEM.
Some women just don't like giving oral sex. If she doesn't like it, has a bad gag reflex why keep bringing up the subject? If you already asked her why she doesn't like it...her answer isn't going to change.
Like your wife I absolutely hate it. It's completely disgusting to me. Why would I put something in my mouth that has urine coming out of it? That's gross and unsanitary. Not to mention I have zero gag reflex. And no I do NOT expect dh to do it to me.
Tell your wife how much you enjoy it and how fulfilling it is for you. Even if it's beyond words, respectfully communicate to her that oral sex gives you intense pleasure. Assure her that you respect and the final choice is hers.
Offer to wash *extra* thoroughly, both in front and behind; maybe even invite her to wash you any way, and anywhere, she pleases.
Maybe a little flavoring (chocolate, marshmallow fluff, or something else she might like) would make the experience more palatable. I have never once known a woman walk up to the counter and request penis-flavored ice-cream.
What I'm suggesting is communication, negotiation, and compromise.
Next comes the question of swallowing, but you're not there yet. :-)
Good luck.
Another point may be that if she had some traumatic past experiences with oral sex (child abuse, abusive sex with ex-partners in her life or other traumatic events connected to oral sex), it can be one reason for or contribution to this aversion.
She may have an aversion to oral sex and it is hard to explain...but I have met many women who would never give oral sex to men. Personally, I do not know why and I do not understand this aversion because I love oral sex (both giving and receiving), but it really exists.
In order to identify the issue more exactly, you can try to suggest using condoms during oral sex - I know it seems stupid, but her reaction can show you something more: if it is really only about the TASTE or fear of ejaculation or "male liquids", then she can agree to try it with condoms - all these issues with taste, liquids etc can be solved with condoms - but if she refuses it even with condoms, then you will see that there is something else than just a taste. Maybe aversion to the act itself, aversion to penis, nobody knows - it also depends on how sexual she is in general, for example my ex-partners who refused oral sex (yes, also with condoms) were not very sexual in general, so it may or may not be related to it.
Good luck, anyway...
I have never ejaculated in her mouth but she just don't like to take my penis in her mouth. What may be the reason?
Is it the taste of your penis or of your semen that she doesn't like?
It does seem that there are more people who dislike being on the "giving end" as opposed to being the "receiving end" of oral sex.
But anyway, if it's a matter of taste... consuming fruit juices, especially pineapple juice, enhances the taste of the ejaculate. Now, if she "feels uneasy" and, I would assume that that means that she either has a gag reflex or simply doesn't like having a penis in her mouth, then there's really nothing that you can do about that... except, accepting it.
Either respect the fact she doesn't want to do it and keep doing it for her or stop doing it for her. If she doesn't want to perform oral sex she doesn't have to.