Should I ..or not ?

My bestie broke her hand, and we rushed to the hospital ... and got her treated ..she has a cast now

The doctor is really attractive, we began flirting, and eventually went out on a date . I did not tell my bestie yet, because she has a thing for him now... he has asked me out for another date..things r so good with him ..

I don't know if u should stop seeing him, because I care for my bestie .. and I don't want her to thing .. i came in between or something