I have the same bug, i can't get the ticket, and janice have 520 point.
Somebody know how resolve this?
When John/Dad is home, you have to go that entire week without engaging in any shenanigans with Janice/Mom. Then on John's last day, be in the living room at 1700h when he departs; immediately after, Janice/Mom will drag you into her bedroom for some boom boom (and depending on your choices you may get 'caught' by Julia/Sister and have a threesome). After this, you will lie in the bed with Janice/Mom and talk about getting rid of John/Dad. The next time John/Dad is home, go that whole week without doing anything with (or to) Janice/Mom, then on his last day go to the living room
before 1700h and you will see his luggage and plane tickets, you can then click on the tickets and take them. Be in the living room at 1700h, John will leave, and Janice/Mom will drag you into her room again, you will engage in some lovely fornicative activities, and John will come back after realizing he doesn't have his plane tickets and catch you with your dick inside his wife/your mom. (AWKWARD) You'll see several dialogs and then be presented with the choice of kicking him out a la Eric in Big Brother, or allowing him to stay which more or less cucks him.
I haven't tried the kick-him-out path, but the only thing you lose by cucking him is the nighttime living room scenes when he's home are locked out because he now sleeps on the couch.