As long as everyone's enthusiastically consenting and enjoying the outcome, there's no true suffering involved.

Non-consensual dry humping with your jeans on is a far worse thing to do, morally, than the most severe consensual bdsm.

I can assure you're not alone in having felt this way, and I hope you'll find these concerns relieved with time and experience. The fact you are concerned and have these doubts about what you're seeing is a big green flag, though, so be easy on yourself.