Most Helpful Guy
Up to you. There's no set time for these things. For example, the girl I'm currently seeing..
1st date - Casual get to know each other
2nd date - Started becoming more intimate
3rd date - She asked me if I was just in it for fun or if I was interested in a relationship. I said I was open to anything but wanted to take things slow.
... Fast forward to about the 6th date, we both agreed to become exclusive.