“ You don’t plant carrots and then pray for melons.”
You can harvest carrots then exchange them for melons, but I think at this point the analogy sort of breaks down.
I know guys who met their wives in a hookup culture dating situation: they were looking for sex and fell in love.
When one told me he had proposed to his girlfriend, I asked “Did you go down on your knees?” He replied “No, up on my elbows!” He’s been married for over 25 years now, after “planting his carrot” as you euphemistically put it.
I’m not going to tell you what he calls his wife’s breasts: that would be the final death blow to your analogy.