It’s natural for woman to fake orgasms as often they either want to get things over with because penetration might start to feel uncomfortable (and if that’s the case consider lube and more foreplay into your sex routine) or they struggle to reach the big O and don’t want to offend their partner by informing them they haven’t been able to get her there. But the issue is that no one else is responsible for your orgasms except for yourself and this need to fake an orgasm out of fear of offending someone else is an issues in itself. Unfortunately that is a bit of a societal belief and also one strongly linked to masculinity so not always the easier to overcome.
The problem now is, depending on how long you have been seeing this person, telling them that you have been faking it might really crush their ego. Instead try not to fake it every time and rather start to guide your partner on how to make you orgasm. There might be a period of no orgasms faked and then an excuse to start looking at a few things or areas to zone in on. Try and correct the issues of not experiencing an orgasm rather than first of all deciding if you should tell.
If the issue can’t be fixed this way then it might be time to tell the truth. However, understand that this might be seen unfavourable and ego crushing. If you are potentially going to crush someone’s ego, especially in the bedroom department, also try and build it up at the same time. Give lots of compliments, especially about their sexual performance and reassurance them of your love and attraction but deliver the bad news swiftly and straight to the point. Also, reassure your partner that you do want to work on this issues and have a few ideas of how you can do it together.