Use a text editor, for example: Notepad, to edit the "glactivites.agl" file in "\singles\gamelogic\" folder. Edit all the relationship requirements to "0".
Edit Character Stats
Is your single, Dull, Messy or too Shy? They needn’t be any more! First of all play the game and save it, then quit the game. Open the 'savegameXInfo.dat' file in notepad (X is the saved game you want to edit e.g. savegame3Info.dat)
You can find the file in the ‘savegame’ folder where the singles game is located. Now search for 'characterConditionValues', when you find it change the values
Because you have two singles do another search and edit the values again. Now run the game open your saved game.
If the stats have not changed click the switch character button.
Extra Money
Use a text editor to edit the "savegame?.dat" (where ? is the number for the saved game) file in the "savegame" directory in the game folder. Search for the word "money" in the file and change the number behind it to "999999".
Having Children
While two people are in the middle of making love, save the game and then exit. Soon later, restart the game, and load your saved game. You will notice that there is a baby by the lovers.
Modify Money
Locate the file "game.cfg" in the config folder of the game's installation directory. Open the file with Notepad and search for the word "money". Change the amount to 999999999 for max money.
More Skill points
You use skill points to make your singles better at doing tasks therefore taking less time to complete and giving your spare time to wash (it seems like I'm forever washing!). Here is how you give you Singles flat mates more skill points.
First of all play the game and save it, then quit the game. Open the 'savegameXInfo.dat' file in notepad (X is the saved game you want to edit e.g. savegame3Info.dat) You can find the file in the ‘savegame’ folder where the singles game is located. Now search for skillpoints, when you find it change its value to 30 (This should be all you need to max out you single) -> skillpoints = 30.
Because you have two singles do another search and edit the value again. Now run the game open your saved game and spend your new skillpoints! If the points don't turn up straight away click the switch character button.