does avoiding mentioning something make it more likely the thing that’s avoiding being mentioned stays off another persons conscience?

for instance: mary and johnny are a couple in high school and johnny was a transfer student last year. johnny transferred from baltimore and they currently live in dover, delaware. johnny is visiting baltimore over spring break and staying with his friend thomas. mary is ok with thomas. he knows in baltimore that johnny was friends with this girl sally. mary does not care for sally for a multitude of reasons. it seems like him and sally aren’t really in contact anymore however mary is not completely sure. mary isn’t sure if she should address the elephant in the room or avoid mentioning it. after all she worries by mentioning sally it might get johnny’s wheels turning and he may make a point to see sally. if johnny already didn’t have the idea to see sally in his conscience, mary staying mum about it would probably be her best laid plan if she was hoping johnny would not see sally. right?

anyway this is a very deep thought provoking question, this is meant for research purposes only. so thank you!