Ask her if you want but that's not going to make you feel any better. She more than likely had no real pre-meditated reason for it. More often than not, the cheater simply has a momentary lapse of judgement at the wrong time, resulting in them cheating.
She might say something like how she felt neglected by you, you weren't giving her 'enough attention' for the past little white, etc.. Whichever it is, that's rarely the truth. It's simply an easy way for the cheater to shift the blame away from themselves because they know they fucked up.
Do you think it will help you get over it and recover? Will it help you bring closure to the relationship or will you only be opening an old wound? No one besides you can answer this because your the one who knows yourself the best, whatever you think brings the most amount of closure and relief possible is the best way. Either that be trying to find out why or entirely blocking her from your life, or anything in between, its up to you. Don't blame yourself though, its not you, a cheater is a self entitled brat who need everything for themselves, if they can't get enough out of you they look for the next thrill.
Ok, you need to stop beating yourself up for her behavior. Her cheating is NOT a reflection of you. She has shown you the kind of person SHE is. Is that what you want in your life?
The truth is, it is not important WHY she did it. It doesn't matter. This is an example of the low level of respect she gives partner, and you have higher standards than that.
Don't hate yourself because she cheated. You are not to blame. You did not deserve it.
If anyone here is not good enough for someone else it would be her. She's the one who doesn't deserve your love. Give yourself time to heal from this heartbreak. Not all women are disrespectful in this way. Focus your sights on finding a good, true girl who will treat you with the same love & respect you give her. You'll get past this, I promise you.
I don't know, I think that choice is ultimately up to you but I do understand the need for closure when some one you care for hurts you. So, if you think it will help bring you peace and help with the healing process, then go ahead. However, I do caution you to be careful with a question like that because maybe it can bring you closure but it could also cause you more pain depending the answer she gives you for why she cheated.
I say, weigh the pros and the cons of asking her that question. And, then go with whatever your heart and soul tell you is the right thing to do for you. Good luck.
She did it because she values her pleasure in the moment more than someone she's supposedly committed to. It has nothing to do with you. If she thought you were worthless and had nothing to offer as a boyfriend, she would've just dumped you.
I would say, yes. Do ask her why did she cheated on you. You absolutely have the right to know the answer! Whatever the answer may be, be prepare that you will need to leave her as she does not deserve you.
If you can elaborate what happened, I can give you a better and more detailed opinion.