This might be a bit cursed idea but hear me out!
Peter getting very cheesy tattoo of Elias as a mermaid. He would get it done in some far away port so there’s no chance for Elias to barging in trying to stop this.
For reference he would probably show to tattoo artist a very revealing photo of Elias that he’s been given for personal use which would make the whole affair nicely uncomfortable.
Peter would also make sure it’s at some time Elias doesn’t have any important work to do and therefore he might be watching him. Peter would even for once engage in eye contact with some eye imaginary and possibly wink at it.
Elias would be probably quite angry and he would be filling Peter’s voicemail with angry messages during the whole tattooing process.
Of course when Peter returns and he’s welcomed with divorce papers he acts absolutely shocked and pretends he has no idea why is his tattoo not viewed as gesture of love.
Oh cursed bonus idea. He would actually not get a tattoo of Elias as mermaid but a tattoo of James. Then he would act all suprised: “Oh, sorry Jonah I forgot you’ve changed bodies… Should I get another tattoo then?”
Anyway this horrible thought was contributed by @trustworthy-liar