No matter how good you treat a woman, if you aren't the man who she has feelings for, she'll never appreciate your efforts. Women are loyal to their feelings, they don't care about sacrifices...If you're not the guy who makes her feel things then the reason she's with you is sinister. It's not genuine desire, it's either she's playing nice because she needs something (provision) from you or she has no other options other than you...

And the day she gets a chance to be with a man who really makes her feel things, she'll definitely cheat or dump you, regardless of all the sacrifices you've done for her. To top it off she'll justify her actions because of her feelings.