If you would like ideas: For the janitor job, since the spouse already has a job there, they would introduce the player. Though how they don’t have to work the whole day yet earn twice the cash would have to be explained. [P.S. Alternatively that could just be because the spouse is in charge of buying necessities. But if not…] Perhaps due to an under-the-table agreement with a condition not to complain about any sexual harassment, and of course the option to receive a on-hands demonstration of what such harassment would entail~ [P.S. Come to think of it, the entire job itself might be best as under-the-table, since it doesn't make sense to be able to go in/take days off whenever you feel like it.]
As for street work, if the player has a pimp then it could be as simple as meeting the character and being given the offer. If not then there could be a scene of them thinking it over, having to buy and put on the outfit, and find an alley to “set up shop”. Though since both spouses claim to bring in money in the intro scene it could be the starting profession, in which case the first time they player goes to work a brief internal summary what happened would also suffice. That would also go a ways in explaining why the player character can accept being promiscuous so readily.
As for connection requirements, as things stand sharing the spouse's job would require a high enough affinity which you will not have if you take up Vito's second offer in the intro. And if not already unlocked, for street work a requirement might be for the player to engage in sex with anyone other than their spouse, thereby reducing their inhibitions enough to be willing to make a profession out of it. Though unlocking the specific clients would be a different matter.