They say that if a woman plays with her hair whilst talking to you, she fancies you.

However, if she removes her wig and strokes it on the table, it loses some of its allure.

Explanation: This joke plays on the idea that a woman playing with her hair is a sign of attraction. The punchline humorously escalates this to an absurd level, where she removes her wig and strokes it, making the gesture much less appealing and unexpectedly funny.