With most of the devices now coming with water and dust resistance rating, people do pay a lot of attention when a certain device does not come with that rating. The OnePlus 5 is one of the devices that do not come with an IP waterproof rating but that has not stopped the owners from dunking it into various bodies of water.
More than a few users have come forward to claim that they tried submerging their device and that the device still worked fine after that. While that is good news for those with the OnePlus 5, that does not mean that you should be dunking testing that out yourself.
The device does not come with any adhesive between the display and the frame which means there are a lot of access points for water to sip. Those users might be lucky but you might not be as lucky.