If you want to date girls other than Michelle and Kate, you can do that, but it involves some legwork.
However, there's a lot of fun to be had by partaking in the Liberty City singles scene.
There are two females in the game you must date-Mallorie's 'friend' Michelle and the O'Reary boys' sister Kate-but other than that, dating is completely optional. These relationships take on a more light-hearted and pseudo-romantic tone and are completely optional for the most part. The first type of relationship is any that Niko has with various females he encounters. There are two different kinds of primary relationships in the game.
In fact, without building up relationships with myriad characters in the game, you're going to miss out on a lot of what the game intends for you to see. However, that shouldn't daunt you from building as many relationships as you can, because they happen to provide some of the deeper and more rewarding experiences Grand Theft Auto IV has to offer. The relationship aspect of Grand Theft Auto IV is perhaps one of the most nebulous areas of this epic game.
