Uh oh, an expensive problem

I recently purchased some expensive winter bib pants without a chamois. My reasoning was that they are so expensive, and will be worn 5 days a week in the winter, they would last longer if I got the version with no chamois and just wore my favorite shorts under them rather than wearing just the chamois version and having to wash them daily.

Well, I've ridden in them 3 times with my shorts on under (which is how they are intended to be used) and I have HORRIBLE chafing problems. I almost can't ride now. I'm sure I can't return the pants, since they have been worn. I'm guessing that the outer pants are tight and somehow causing the shorts underneath to be in a different position than when I wear the shorts by themselves. I was careful putting them on, I don't see any bunching or creases, but obviously this outer layer has changed something. I've ridden 6000 miles this year in these shorts without issues! BTW, DH uses the exact same winter pants over his regular shorts with no problems at all.

What can I do?

get the next size up? take them back they are a failure!

Have you tried wearing a chamois-liner underneath them rather than full shorts? This is what I do with my winter tights - I love the Terry short liners that go with my baggy mtb shorts so I also wear just the liners with my tights. It prevents a problem developing from possibly too much material.

Which bibs did you get, and from where? Is there any possibility they are too small? Considering they have no chamois, perhaps they would consider an exchange? Just tossing some ideas out there.

Depending on where the chafing is, maybe a bit of Body Glide might help?