best friends ...forever!?!

I have these 2 best friends (A: my age, B: my senior college mate) from the opposite genders, which I guess is normal for anyone. Back then (not now though) all of us are singles. But there was a time where A happened to show interests in me. I was kind of into her too but B’s characteristics are much more fascinating to me. I might have problems choosing between the 2 but I realized that the friendships between us are much more important to me.

Now, let’s just say A (because she’s working like 2 states away from me but we do keep in touch) is still my BF but is a bit distant compared to B. A few days back, I was out with B & another friend for our friends’ functions. During that time, we talked & came to a point where she told me she’s just started seeing someone already.

In a way, I felt honored that she’s able to share that personal info of herself with me. But there’s this mixed feeling that I’m going to lose her company (maybe as a best friend) although I’m dating someone. When A started dating her BF, she even neglected her roommates & all but I don’t see that in B. Even when B started seeing someone, she still can have life with other people, including guys. 1 thing B said though, she still have life with other people but her BF kept her on toes.

Do you ladies have any input into this situation here? I’m not sure but I felt like the bond seems like breaking (as it once happened with A). It’s hard enough not to choose between the 2, but to severe this bond, I think it’s harder and I don’t want it to happen. Is there any way for this?