How true, you aren’t having sex flaccid. I suppose if you are imaginative, good with your hands and tongue, you could. Sex isn’t all about penetration, even if it is the main course, after the entree and before dessert.
I liked the first post. This is not a masturbation site. Good I don’t masturbate. So far, since December 2017, I have not experienced any gains, and my erection size looks the same to me, I doubt I could see 0.5” gain anyhow, and I am thinking of other things than measuring my erect penis. Just how much trauma do you think DIYgrower needs? I have learned that jelqing hurts, my circumcision scar stings from the get go and for an hour afterwards. Pumping, Bathmate, gave me a purplish penis shaft with lots of broken veins, stretching in lots of ways and using an ADS gave me a sore glans. I wrap very carefully, follow instructions for the pump, and use sufficient force yet I have experienced discomfort and some pain. So the OPs idea is not quite right.