I would have a belly laugh at this posting if it did not indicate the (truly) dangerous way in which some jewish circles (mainly chareidi) are drifting. To find evil intent and dubious motivations in every act of someone is totally NOT torah-dig.clearly, “heve dan es kol odom lekaf zechus”
If you feel that it is inappropiate to invite couples because of the possible inferences, then it should be across the whole spectrum. People’s inclinations do not stop when they have children or as they grow older. Mayb even qite the opposite.
The fact is that this has never been mentioned in halacah, it surely goes against the grain of one of the biggest mitzvas (hachnsos orchim) and it brands (unfairly)every person.