Extensive discussions in most darkrooms are for bidden.
Communication is almost exclusively through contact and body language.
In the following ways you show that you are interested in sex:
• Is the darkroom not totally dark, it is apenetrating look sometimes enough to tempt anyone.
• Do you walk past someone you like, you can nudge him with your shoulder.
• With a hand on his shoulder, on his stomach or buttocks make clear your interest.
• An even more direct message with your hand on his crotch.
• If the interest is mutual, you may proceed.
It is difficult to estimate in advance one's borders in a darkroom. You can do this:
• If someone groped and that's not you, then push his hand away.
• Respect it as another indicates that he does not appreciate your attention.