Funny Fountain Pen (Dream)

Last night I dreamed I was in the upstairs of this big house. It has nice wooden floors. I got up early to get ready for work and I was walking around in just my underwear. My Dad was there and he says "Hey Tom, put your pants on." I say I'm proud of my body and there's nothing wrong with me in my underwear. My Dad starts to argue and I say "Hey Dad, I'm just teasing." My stepmother Marilyn is nearby and she says "Hey Tom, you look like a fountain pen!" For some reason I find this to be incredibly funny and I double over in laughter. I'm laughing so hard that I'm not making any noise. My laughter would start to subside and then I would visualize a fountain pen and start laughing even more. My Dad was wondering what was so funny.