Sad to say, hubby has a point. As Eden put it, you move around a lot while riding whether you realize it or not. Even if you don't stand, your position changes slightly as the terrain changes from flat to hill and back again.

That said,
+ check the angle of your bike with respect to horizontal. Your bike may be slightly inclined, thus increasing pressure on sensitive tissue. You can compensate by adjusting the front wheel or tipping the saddle down for indoor riding.
+ Stand more. No time like indoor riding to really build up the standing muscles. Even if you're not a rider that stands outdoors, stop signs, stop lights, etc give your butt a rest. Standing indoors mimics that pressure releif.
+ If you're going to stay on the trainer for more than an hour, consider changing shorts 1/2-way through. No matter how good the fan, you just don't get quite the air flow to keep them dry indoors. Wet shorts can be more irritating and...well...flora and fauna....

This year I tried to use an old saddle indoors instead of my Brooks. Big mistake. I lasted about 50 minutes and was standing every 30 seconds. Ouch. Put the Brooks on this weekend and managed 2 hour rides -- chafing from the short seams, but saddle-wise I had no issues.