I'm not totally sure about delusions of persecution specifically, but I have definitely had messed up reactions affect my relationship because of my PTSD and childhood abuse history. I've had a lot of trouble having a healthy relationship with sex. Ive had problems with some forms of intimate touching. Stuff like sudden reflex reactions to being touched. Like id be touched and instinctively jerk away like I was being attacked. Other forms of touching just make me feel sick and disgusted. Over time ive gotten better, my bf was very patient with me and never pressured me and that helped a lot. It still happens from time to time. But less often. Touching is mostly not a problem anymore. Though I stil feel sick if he touches me in certain ways. But rarely have the startle responses I used to have. Suddenly trying to defend myself from innocent gestures. Sex is still something I have trouble with not instinctively disassociating from though. It sucks, cause I do like sex and want to have sex with my bf. It's just been difficult for me to get into it. To not have my mind shut down and to stay 'present'.
PTSD can definitely cause some messed up reactions in situations like these. The part about affection triggering instinctual defensive reactions is definitely something ive experienced and had problems with.
