good to.bad thanksgiving

Having a good Thanksgiving for bout an hour until we got on the topic of my baby father. Talk was good for about 5 to 10 minutes, until it went for a turn. Not sure why it bothers me so much. But my aunt and uncle start talking how he cheated on his ex wife. How he secretly seeing someone who's married and screwing her. Note he's my aunt's and uncle friend. But now I'm in the dumps again. Him and I aren't even dating so why does it both me so much. They also said he most likely won't return from visiting his sister in Colorado. He plans on leaving in Jaunary and said he'll be back March. I'm due in May. But now I don't know what to think about him anymore...