I wouldn't use relationship as a ressource here, relationship is the most valuable ressource and there are little situations where you would go for morale instead. It also would change the game mechanics a lot. What I could imagine is a money/morale tradeoff. While doing things for money doesn't really fit a private party (might better fit stern male), you might meet certain people at the party. If they enjoy your company, they could use your services the next day. In other words, if you accept some lewd actions on the party, you loose some morale, but get a guaranteed passenger of even VIP mission from that officer the next day.
Still, I'm not sure that implementing new features at this stage of development is a good idea, or whether this should be postponed for later.