If you've known that they are a pair prior to beginning of your activities, then your actions are pretty bad.
But any way, I (inexpirienced in love) think that you should not tell the boyfriend about it, but you also should stop seeing each other.
That is just my opinion.
But any way, I (inexpirienced in love) think that you should not tell the boyfriend about it, but you also should stop seeing each other.
That is just my opinion.