First off, congrats on riding with a lady friend (even if she is just a friend). I could never get my ex to ride, and really wish we could have spent more time actually "doing stuff" rather than "hanging out".
As far as seat reccomendations go...I have a few pilonidal abscesses that get irritated by cycling. They developed in college after spending long periods of time in a hard wood chair, writing papers. Opting to not have surgery and live with them has made my seat choice and bike set up critical.
RIght now I am on a Brooks B17 Imperial. The imperial designates it has a cut out to relieve pressure on "that" area, which is has done with candor and grace. Give it the time to break in and it feels amazing.
I think with your situation, you would benefit from a wider seat such as a Brooks. I learned from the owner of my LBS that pressure along the central line of ones backside is caused the sit bones not being properly supported. A too narrow seat will not support the sit bones, leave the "goods" (whether in the front or back) to take the brunt of your weight. Also, gel seats and cushy foamy things are bad as well, since they let the sit bones sink in and still place pressure on the "cash and prizes".
So essentially what I am saying is, is that I feel your pain (literally and figuretivly) and suggest trying something a tad wider, possibly a Brooks, or something else designed for a wider sit bone region. The extra weight is totally worth it though as far as a Brooks goes, and I am sure others will recommend them as well.