Make sure you turn skipping on, then skip through all the xxx scenes. Click on the correct action as they come up.
Note: parenthesis are some extra info i have added, it's not part of the choices given.


This is the choice path I took to get the achievement, but it can be done in other similar choice path ways.

Pay Yourself (Jennifer pays cab driver)
Wait for Mark
Go Shopping
Take a shortcut
Try to bargain (with Jimmy)
Suck his d!@k (Jimmy's member between his legs)
Walk through back alleys
Crouch (In Dean's office)
Ask Kelly out
Hold Kelly's hand
Pretend you're asleep (at the Club)
Go crazy (In elevator w/Mark)
Take a sip (In Dimitri's)
Give him a show (Jennifer shows Mark, in apartment)
Go to Jimmy
Throw it away (Gun)
People (In Dimitri's)
Console Dimitri
Don't (Do Not Take the pills)
Leave it (Don't use sex toy)
Stay hidden
Stop him (Don't let Mark attack Jimmy)

After Jimmy is arrested and Several years later
Jennifer is talking with their daughter, Mark finally says "Too bad she looks nothing like me." Achievement will be gained.