The first thing I thought is what do you want to do. You answered that question.
I would ask D19 if she wants alone time and see if joining them is something she would welcome. I am pretty sure she would be ok with you being present.
So, are you strong enough? Is this going to send you spinning? Personally, I think you are strong enough, and should go. It is ok to be curious. Keep away from any relationship conversations. Treat him as a business college or associate, not someone in your inner group of trusted people. I am confident you can and will be able to do that.
DnJ
Feelings are fleeting. Be better, not bitter. Love the person, forgive the sin.
