Sounds like you need to communicate your desires. This is not limited to extroverts. It’s harder for us introverts but not impossible.
I’d ask for them to stop. If this isn’t followed, something written. If this isn’t followed, time to involve someone higher. I’m very reluctant to involve HR, they’re going to fuck with you very likely. However, your supervisor’s supervisor might be able to help. Important to slowly escalate and make a paper trail if the initial verbal ask doesn’t work out.
Also, did I read that correctly that sex is being discussed? As in sexual intercourse?
Tiny needles make it pretty easy, if you can do phlebotomy you can shoot up with a 31ga needle. I was in lab tech school in the military and ended up shooting dope sometime in the 00s, but stopped before I got in any serious trouble. Those people who have to hit weird veins in odd places because they’ve ruined the rest blow my mind though. I guess if it’s between that and being dope sick it’s worth it in the short term.