X = ex
Y= older brother, dating prospect

given this situation, what do you guys think? ESPECIALLY if something like this has happened to you, if u have older brother etc.

-the honest truth: this has nothing to do with X; no revenge or emotional manipulation intended.
-I started the relationship with X.
-X and I went out for 4 weeks over a year ago, and kissed TWICE.
-X was apathetic, he never called me and was flaky, so I broke it off.
-i was never introduced to parents of X and Y as X's girlfreind(by my standards, I never really was his girlfreind) although I know the parents and they know me
-Y was not involved with me and X's relationship, I still need to ask him if he even knew about it.
-Y is a completely different person.
-i am in a completely different time of my life.
-X is in a completely different time in his life.
-X and I have not seen each other or spoken for 6 months.
- Y and I have some chemistry and I wouldn't mind datin g Y if that ever came up. We never talk about X, I would not bring the situation of X and meup unless Y wanted to date me. I would want to know if Y was okay with this situation first.

I know others will perceive me as a whore, but I only really care about me and Y, X and Y brother to brother relations, and the emotional welfare of X, my so-called ex.

It doesn't even really sound like you and he were in any type of relationship.
It sounds more like you were checking to see if you might be interested and it fizzled out. The only problem I see is what does his older brother say and want? How will you handle it if others do see you as too loose and easy?

Assuming this is not a math test, all of that X and Y but yes this is not that uncommon,