i had an issue similar to this, visiting a fellow friend of a friend while out helping them film for a movie they are making.
after many confrontations - and iterations to my gear/juice/vapor - it comes down the simple fact "they dont like how it looks like smoke and it is in their space"
first was told its unhealthy and im clouding the room with poison and his parents dont allow smoking in the house(tho one of them smokes a pipe in the kitchen.. all utensils on a plate ready) - recently started dripping, and for the special occasion of being at this kids house(knowing he thinks its poison) i was vaping JUST vg. no flavor, no nic, no PG.
as the VG being used, i was told "it smells like baby poop" - HAD to laugh in his face, he was imagining things - VG was odorless.
continued to vape, and then was told that im going to give him nicotine poisoning/addiction from being in the room - i had to reasure him a second time, it was JUST vg, and nothing else, no flavor or nic or W/E. - unless your alergic to vegitables, then i have no reason to stop besides you "dislike the fog"
third time rolls around - mind you this all is happening within 20mins - "STOP FOGGING THE ROOM. I CANT THINK, IM GETTING DIZZY"
i calmly walk him over to the PC on the desk, pull up a spread sheet for childrens tylenol - "IF this is safe, and cant make you tripp balls or halucinate or w/e your experiancing now - how is THIS making you trip? what im vaping is theoreticaly safer then the tylenol - its missing ALL the ingredients but the liquid catalist - VG"
apparently not firing any brain cells, i was told his parents are going to get mad at him, and that i need to go outside now.
last remark i made walking out - "if one or both can smoke a pipe in the house i dont see the issue, but if you insist they will have a problem and yell at you, tell them to take it up with me and talk to the direct problem so i can educate them since maybe they are more accepting than you to learn."