Am i a lesbian or bisexual??

I am 28,independent beautiful,unmarried woman i am in a serious relation with my bf since last 4 yrs…i love him a lot and he too loves me and cares for me…i was getting bored yesterday so i just thought of visiting a random chatting site…i met a married woman we started to talk about normal stuffs… then she started sharing about her fantasies with her husband…she also shared that she want to try with a girl….as soon as she told me this…i thought of asking her to get naked…(just for fun) and i was shocked to my surprise she started u********* … amd she asked me to do the same…i also undressed thinking that it hardly matters she is just a stranger…then she started masterbating in front of me…i too was just rubbing my clits to see her reaction…she started doing it faster….i was just thinking that may be she is not satisfied with her husband and she is not very attractive rather she was fat…but i dont know what happened to me after that i too started to rub my clits faster and faster with my legs open and rubbing my n****** wildly and moaned like never before…it was heavenly…and m still getting wet while writing this…i just want to know if i am a lesbian….bcz i enjoy it with my bf too…i hv had o***** with him too…but how did this happen??? Plz let me know and help me to discover myself