Search Results: checking out other girls

I recently found out that this guy i really liked played me. Well, he played me and this other girl, his girlfriend ( how iconic ). I was friendzoning him for months until he actually got into my head by manipulating me with his words and i was in love with this guy regardless what my type in guys were. He is the exact opposite my type by looks and so am i to him. We both like blondes, blue eyes etc. Ofc i knew that he only wanted to get into my pants because i was a challenge. I was always talking about him being my friend, parties and other guys. I ignored this fact that he only saw me as something he could win. I also ignored what everyone else told me about him. I ignored that he panicked when he got notifications on his phone when we had sex and i ignored so many other things!! Im so stupid for falling for him and I hate myself for it. However i hate myself more for not checking up background of his dating history before sleeping with him. When i found out he had a girlfriend this entire time i got really mad so i confronted him about it. He came with an excuse and said that they were broken up when we hit it off but I dont believe him. He was trying to get me for months so even if we didn't do anything when they were together he still cheated on her. I found her instagram yesterday. She is gorgeous, blonde and everything im not. However I always support girls and I personally would appreciate if the girl my boyfriend cheated on me with would tell me that. I never knew he had a girlfriend, i still feel bad about it but i want to make it right. should i tell her or should i just leave it alone? Im Done with this guy and i honestly want to enter 2019 without guilt. What should i do?