Each of them has her own wants, which her boyfriend should have.
If the girl is possible to pick up, you'll notice a blue arrow above her.
These include a visit to a restaurant (including fast food chains, diners, formal restaurants and bars, alongside the bar in dance clubs), dancing at a dance club, and driving around.
Each girlfriend has their own different tastes to the three activities, as well as Carl's physical appearance.
Barbara becomes available once Tierra Robada, Bone County and Las Venturas are unlocked.
You get 10% with millie everytime you visit her, so 10 visits and your on 100%.
The other girls, however, are harder to get 1005 with.
Michelle is the only girlfriend who is found in an interior.
Three different activities are available during dates.