If you wear pants in bed are they clean ones just for bed or are they the ones you have worn all day?  and do you have 2 pairs on each day? clean ones morning and for bed? I shower in the morning and have a bath or shower each evening before bed so my body is perfectly clean without pants.
Wearing the same knickers I'd been wearing all day to bed would be grim!
I have a stack of cotton boxers in a drawer with my nightwear, along with a stack of pyjama bottoms, and sleep t-shirts and long sleeved tops. Plus different socks for evening - wearing the socks I'd been wearing to work in bed would be minging
Clean boxers, socks and top for bed every night. Pants under PJs means can wear PJ bottoms for a few nights without needing a fresh pair every day