My relation with a married women

I am a married man. I always been attracted by womens and I ahd plenty of girlfriends in my life but never I hidden my marrital status with those ladies. But presently I have a girlfriend who is my collegue and a very happy wife of a very good person. I mean they are a happy couple. our relation created suddenly and as the time going, she is getting crazzy, she wants me in bed every week. if she can every day. I am afraid. I dont want to hart her. but how can I positively convince her to stop. she does not want to listen anything about that. please suggest

i think you need to confront her and tell her donotexpect me to be sexualy active every night ,or you can use diffrent ways by 1\ reaching home when she is asleep 2\leave early in the morring before she awarke. 3\tell her that you are on some medication and need to abstain.