How to explore sexuality?

This may be a weird question, probably without any real answer; but I have this need to know how I can explore my sexuality (without cheating on my bf). Some background: I am male and 40 years old; I always considered myself straight- but was always open and curious about same-sex relationships. I was married to a female for 18 years, I lost my virginity to her when I was 21. Lame yes! Lol. I never fooled around with anyone and never cheated on her. Our sex life was very vanilla. Over the last couple of years of our marriage she developed several mental illnesses and last year I discovered that she had several affairs. The marriage ended. Soon thereafter I met a wonderful man (14 years my junior) and we fell in love. We are now engaged and living together. He has a very promiscuous sexual past and does not want to discuss his past sex life with me, claiming that he is ashamed of everything he did when he was younger. I can understand that. He is the second sexual partner in my life. We are very happy together, and the sex is great, albeit somewhat plain. When I propose some kinkier stuff he freaks out saying that it reminds him of his past. I however feel very sexually inadequate and inexperienced. With this feeling of sexual inadequacy, I have this 'need' (for lack of another word) of exploring my sexuality, being gay for only approx 12 months now and having only two sexual partners. I love my bf and will not cheat on him. We are in an exclusive relationship. My dilemma is therefore how I can explore / find myself without cheating on him. And by sexuality I not only refer to the actual deed of sex. But more the fact that I changed my sexuality halfway through my life. What does it mean to be gay? Should I act/dress differently? This new life is all very new to me. If I have to put myself in a box it would probably be as 'pansexual'. I have no gay friends I can discuss this with. I have looked at gay porn but does not believe that to reflect real life. I am not sure if my question came out right; as I do not know how to phrase this 'need' I have. Hopefully someone can give me some advice.