Why do men ride women's cars and lead women with girders?

I read a joke, which is similar to your question.

I went to a class reunion alone and had a good chat with my first lover.

After the party, the man offered to send the woman home.

The woman sat on the beam of his bicycle and went home.

After returning home, the man felt very tired and fell asleep.

The next day, when the man went to work, he suddenly found that his bike had no girders!

Ha ha! Do you understand?

And bedding! "After returning home, the man felt very tired and fell asleep." Ha ha!