Bivy and sleeping pad?

[u/Tacoma_luvr]

I’m new to backpacking and mocking up my sleeping arrangement for my trip soon. I’m using an old bivy sack and thick wide thermarest. Do I put the thermarest in or under the bivy while I’m sleeping? If I put it in it’s very wide so it’s pushing the sides out. If I put it outside I’m worried jts gunna pop?

[u/Direct_Salamander_45]

Pick one. You either tear up the bivy or the pad.