Is it normal that i'm not gay , but if i think about it desire it

I am 61 years old , happily married for 36 + years . I have had a few indiscretions with a few woman that were massage therapy girls and a few others . I am totally straight and never think about guys , but when I look at porn or other sites and since its so easy to get guys to engage in conversation. I can totally get the urge to do everything with a guy and have on several occasions. It's so easy to get off with a guy , they don't require all the hassle of courting a woman . We are both on same page , to get off and be done . I feel bad after but totally into it at the time .