you get the fair by doing bernards night date, the first time he gives you 3 options
1. New houses
2. The fair
3. Defensive aspects.
All 3 have there own scenes and the order I listed might be different in game but the fair is entertainment aspects when talking with him, also you need to have cured bernard and logan for him to do a night date. Also bernard needs 2 hearts to invite you for a date to get the 3rd. I think it you need 3 hearts, pretty sure it's 2 and the date gives you 3.