I think this has to do with balls and butts on necks and shoulder. Friction, excitement, potential engorgement how to react or not to.
When you're you, your own sexuality. You generally don't think about the boundaries of touching. But when its someone else's naughty bits, its odd.
Like I had to change my mothers adult diapers and clean her nether regions, lady parts, twice a day and bathe her in a tub. She was 5'2 and 250lbs. The first day she adamantly refused but by the second I had to do it. It took about a week to get down just the physical safety and work around but I was glaringly aware of being all up in her business. She found fascinating spots on walls and ceilings to study as her adult son tried to discern what was a clean cooch and what was being obsessive and how to get a breast to naturally flow, fall into a brassierre rather that grab that putty sack and just pack it in.
Week two, I was a pro.
Week three she complimented me out of nowhere and said I was really good at cleaning ladyparts.
There's a weird propriety we're all socially engendered with about bodies, genitalia, especially when you're not a medical person or sexually involved. The awkwardness fades over time but soooooo much is made of genitalia that when you're confronted with it, it can be like close encounters weird.
Sure I've changed babies, washed small children, had a friends son just reach over poke me in the penis as we peed together and laugh hysterically. Children we tend to barrel through boundaries and allow them liberties. Adults, it is still weird.
I think that lgbt people hear lgbt and run to get their flags and start using their tolerance voice when the question Is really from the place of a dude having another dudes manjunk banging and rubbing against his head, which is like really near his face, and how to be cool as you realize yes that is manjunk all up in your afro and assbutt all into your shoulders and said manjunk and assbutt owner likes dudes holding, resting propping his manjunk and assbutt , you dont want to be a square but imagine your female friend said sure, you can have some money, its in my bra, dig in. You dig in and rifle amongst her night and days, are we both going to pretend, that one of us who really likes or dislikes night and days isn't thinking,about that they're rifling through night and days?
There were moments in my spic and span mommy scrub a dubs where I thought about, hey, I came from there, that's what it looks (and feels) like and I looked up and she was looking at me, knowing I was having such thoughts.
Odd. Just odd. Human odd. Adult human sex and sexuality, not covered in the casual manual odd.