Penises help with roofing - no really.

I have volunteered for Habitat for Humanity almost every weekend for over 15 years, and have done just about every aspect of building and construction.  We were building a house and a new volunteer said that he would take over for me on the roof because it would be “easier for him”.  I jokingly said, “Why - do you actually use your penis in some way when roofing?”.  He answered that, yes, indeed, his penis was a “stabilizing factor” that helped men not fall off on pitched surfaces like roofs, and that testicles, in fact, were known to improve the ability to focus, so that he wouldn’t do things like hit his thumb with a hammer, which women were prone to doing.  I thought this was a witty retort to my slightly rude question, and was thinking he was a pretty clever guy to joke around like this.  So, I laughed out loud, thinking this was friendly banter.  Instead, he was seriously offended that I had laughed, and said he was just trying to explain basic biology to me!