How about instead of faking an orgasm, you just tell her (in a very nice way) that it is just not going to happen & you don't want to tire her out or rub her raw. Make sure you tell her it does NOT mean you aren't turned on or are going to be left unsatisfied. If she doesn't believe you, turn it around on her by asking is she thinks sex is poitless if she doesn't always cum, or if she doesn't cum does it mean the guy did something wrong?
If you absolutely can't handle telling her the truth (albeit a sugar-coated version, perhaps), the short answer is yes, guys can fake orgasms too. I had a friend who was a male escort who would do that all the time. Just do everything you would normally do when cumming: breathing, sounds, movements, etc. It is true that some women can feel the ejaculation, even with a condom on, but they are not going to be able to feel well enough to tell for sure if you aren't ejaculating. Then take the condom & dispose of it quickly.
As for bareback, that is a lot harder, but if you use lots of lube or she is very wet it might be possible, & you could try saying something like "Gee, I must be dehydrated, I didn't ejaculate very much this time". Or you could try quickly getting her a warm cloth & wipe her pussy so that she thinks you just wiped up the cum. But bareback faking is going to be a lot less believable...
*Also: another tip for having a real orgasm, is if you can't cum through intercourse, try getting her or yourself to finish with a handjob. That might help, & you could always try to make it seem intentional, like "I think it would be so hot to cum on your tits," or, "I like finsihing without the condom on," or, "I want to stroke myself while I watch you masturbate."
