A Nikki-Jay is when an individual invites themselves into a personal private conversation that is happening between two people; creating an awkward atmosphere. Sharkey and Susie were having a conversation about making chips in the slow cooker and Nikki Jay involved herself giving unwanted advice on how best to do this; thus doing a Nikki-Jay.
What the...did she just do a Nikki-Jay in our private conversation?!?!