I Want a Real True Love

i full in love with a married man and we made love with each other but i didn't regret about what i did like i felt happy and i met his wife she was good and i knew he still loves her but at the same time wanna have sex with me i dunno but i know that's cheating and not good but i really liked him and he promise me that he will never leave me and i told him that too but i am not sure about our relation .... i need advice should i become with him forever or leaving him and just disappear from his life?