put all one's sperm in one basket

(verb) To make major life decisions based solely around an anticipated, currently nonexistent, and typically unlikely, future relationship; said of a male.

I feel sorry for Joe. He quit his job and moved to Los Angeles because Jane was moving to Los Angeles, then Jane met a guy down there and Joe hates it there. He put all his sperm in one basket.

(the example should include "put all one's sperm in one basket" verbatim, but that would be bad grammar, so I have to write it somewhere)