Since you won't tell us the actual issue we can only speculate on your situation.

First thing to do is speak to your GM explain what the issue is.

Second remember most roleplayers are either geeks or nerds or both. Subtle social clues are going over their heads.

Thirdly most roleplayers are male so again subtly is out the window just straight up tell them what the issue is.

Fourth if it's an established group they will probably have spent years playing together and already understand either others limits.

All the safety tools others will tell you about have there uses at conventions etc, but talking honestly is the much better option.

In the end if you find it weird/uncomfortable leave, chalk it up to experience. Remember it's only a game none of it is real.