Thanks for letting us know about the pajamas!
If you're playing the free version Shiloh's swimming date is unavailable. That's a DLC exclusive event (the work uniform also can't be unlocked in the free version). If you have the paid version you'll need to unlock the beach date spot, have Shiloh as your official boyfriend, and be in Spring/Summer to have the option of watching his swimsuit date.
Hopefully that helps! Thanks for giving the game a go.