Nothing New in the Good Ratings
So here's my take on this.
I don't think it's about masturbation; I think it's about sex, perhaps an orgy. There's a lot of people, men and women around the pulch that feel that happiness. Terry and Derek are instant friends though they've never met, so perhaps its promiscuous, homosexual encounter. He says that collard Craig isn't in, so they "pass time by". An allusion to foreplay, I'm thinking.
Collard Craig and the suits are very simple: condoms.
Luxemburg does have me confused. My best guess is that it's sexual drive. Notice that males lose their sexual drive the second they orgasm, so that'd be my guess. Though the "orgasm" happens after Luxemburg is dead, I think the time shouldn't confuse anyone. The reassuring arm is a form of masturbation perhaps or, because it is portrayed as a woman, I have another idea:
During sex, it isn't unusual for a guy to lose an erection, perhaps because of nervousness or whatever, so he'll have a little bit of wanking beforehand, even from his girlfriend. So, that's my guess.
That should do it. Let me know if that helped.
Good job, Firth.