Overreacting or inappropriate?!

I was out with my friend helping her shop for some stuff. We were supposed to be out until 5, but we came home at 4. We walk through the door and my kid(he's 14) was walking out of the shower and had a towel around his waist. He wasn't expecting is to be home for another hour so that explains that. My friend is just staring and my son gets a bonor and turns bright red. I tell him to go upstairs and put on some clothes so he does. She says to me "You didn't tell me your son was so well hung! He's got a lot for a 14 year old!" I was so uncomfortable with that comment. I thought she was gonna laugh and say just kidding but she just giggled a bit to herself and talked about something else. I just told her I had other stuff to do and that she had to go home (politely). She seemed a bit offended but that whole comment rubbed me the wrong way. Am I making a big deal out of nothing?