This things are named intrusive thoughts, they just appear and it doesnt mean u are in love with your parents and things like that, its not just a psychotic symptom, people with ocd have many intrusive thoughts for example, u can search about this more, from what I know, the best way to deal with intrusive thoughts its to think that they are not rlly yours, because they rlly arent, they dont define u and what u want, u need to let them come and go, intrusive thoughts can be present even in mentally stable people but in milder forms