“Do you ever just put your arms out and just spin and spin and spin? Well, that's what love is like; everything inside of you tells you to stop before you fall, but for some reason you just keep going” ― Alice Hoffman
Keys can also represent that something is needed to unlock something else. Marriage unlocks Portia and Nerissa from the chance of being inferiorized by the public. Saving Antonio unlocks a chance to have Bassanio and G in debt to them.