It comes down to how the operator views having sex with someone. I'm playing an operator in our current game, and I've done exactly that: had sex with people with the (as a player) hidden motive that I will get +1 juggling and hopefully come out on top. So far young Transfer has fucked two people:
- Manja, who is the most beautiful girl he's ever seen, and who runs an establishment in one end of town (pretty much an NPC Maestro d')
– The Patriarchy, who is an old man who runs the bustling marketplace and bloodsports arena in the other end of town. Transfer wanted to set up shop at his place selling drugs, maybe stationing one of her crew there at all times doing business, and fucking The Patriarchy seemed to be the fastest way.
Now, both of these people mean a lot to me, to Transfer, and to the game. If I screw up "Keeping Manja happy", Transfer won't be happy – from the outside view it's probably mostly infatuation with a beautiful girl who has, for some reason, noticed me (dream come true!), but it sure feels like true love. I work that gig every other session.
"Keeping The Patriarchy happy", aside from being the best name for an obligation gig ever, is also important. If I don't, my little herion tent near the arena won't stay in business, and The Patriarchy is generally not someone you want as an enemy; I do a lot of business in that marketplace (other gigs are surveillance, delivieres and brokering deals). I just got it, but I definitely plan to work this obligation gig now and then. 4-juggling doesn't seem so much now, just as you said – getting new obligation gigs from sex need +1juggling to keep things even.
What would happen if Manja got herself killed? What if I made Transfer kill her? I haven't talked to my MC, but I actually expect to keep all the juggling increases. Because i have to fight for them, either by being plagued by those obligation gigs or by resolving them. Resolving means either spending an advance, getting the people killed (which might not help with The Patriarchy, but instead just transform it into "avoiding The Patriarchy's men") or really working to get the relationship to a stable place. Advancing Manipulate and turning them into allies might work.
In contrast, consider an Operator who has cheap sex with anyone and then leaves them. Now, the rules still creates those obligation gigs, and the MC must still regard them as golden opportunities for complications when you don't work them. So yeah, you're going to be haunted by all those exes. Depending on who they are, you could get them killed but... In a way, the main this shows is how effective a ruthless approach can be – all it takes is that you don't care at all. For the people you got to sleep with you. Fuckin' thumbs up, mr super-Operator.
I say keep the +1juggling from all obligation gigs. The fact that you have them as obligation gigs means you're working to pay it off, one way or another.