Since you appear to be immune to direct questions, I don’t know how to ask you what double entendre, what sexual meaning. I don’t have a clue and you refuse to explain.
What is sexual about vanilla? It just means slighly plain and boring, in my experience.
One of my coworkers was excited about her new house. She was talking toanother lady about all the work she had finished on it. Finally she said, “Now I just need to get the guy to come out to trim my bush.” There was a heavy silence as I felt their eyes boring into the back of my head. But I acted oblivious.
As the office thanksgiving feast was being set up, one of the secretaries put out an email to the whole building: “Does anyone have a meat thermometer in their pocket I could use?”
Vanilla is widely used in BDSM/kinky circles to describe someone who is not into BDSM.
The origin is from the reference to plain, conventional, boring sex. Usually used by people into more kinky stuff to describe conventional sex. The meaning expanded from there.
I always thought this referred to golf. You know, putts. 
The thing is, it isn’t. “Vanilla” has been used to describe conventional boring anything for a long time. Sex is apparently one usage, but also apparently not a major one, given the number of people who don’t get it.
Pfft, looks like you lot need the sage advice of “Mitchell and Webb” (slightly NSFW due to dialogue only)
According to the Online Etymology dictionary, the use of Vanilla meaning plain sex dates from the 1970s. http://www.sunrisescience.com/pages/ystmedia_aa_table.html
Plain-vanilla (as a phrase) was introduced earlier, around 1960s, so it’s fair to say they’ve both been around a very long time that someone finding “vanilla” to giggle about because they know of the sexual reference wouldn’t be that uncommon.
Vanilla meaning plain sex isn’t so new that it’s meaning is uncommon and strange that someone might find it giggle worthy.
Specially medical personnel, who apparently think about sex more often than teenagers do…
Ain’t that the truth…
I always thought the moral of Toy Story was never play with your Woody when you have a Buzz.
I worked for the “analytics” group at a web startup. The IT guy, who had a sense of humor, set up our group listserve as “anal@blahblah.com”. He knew exactly what he was doing. Took a while for management to catch on.
When I took over a project from a departing co-worker several years ago, he had a bunch of files with names that began with ‘cumfile’. I realized that in this case, ‘cum’ was short for ‘cumulative,’ but I still snickered a bit.
Add me to the list of people who’d have laughed at this one.
Or said, “what do you expect - she’s 88 years old, she probably put away her dominatrix gear decades ago!”
I’d have been the guy saying, “Stop by after work, I’m sure I can help you with that.”
The opportunity to drop a heartfelt “Don’t. We. All.” into the ensuing silence would have been far more than I could resist.
My old employer had several labeling machines. Some of them had an arm that would extend and tamp a label onto a box. Whenever the supervisor of that department discussed those particular machines, he referred to them as tampon machines. Sometimes he would call purchasing to say he needed more tampon labels.
Once when I was house hunting, one particular realtor would call to tell me about a new property being available. Some were condominiums. Problem is, instead of saying she had a condo to show me, she would say things like, “I have a condom to show you.”
I had a boss who used to say stuff like this all the time. She had whatever the opposite is of a dirty mind. She just got used to the idea that at some point in one of our meetings I would start laughing uncontrollably for a bit.
The secretary and I crack up over the mailbox slots.
“Do you want me to put this in your box?”
“Can you check my box?”
“Your box is jammed full”
I doubt that’s the origin.
It’s darn close, as the later post indicate. The term plain-vanilla, to imply boring, came around in 1960 and vanilla, specifically referring to no kinky sex, about 10 years later. So the phrase seemed to evolve from plain-vanilla to vanilla as it was adopted by the BSDM folks.
If you have info to add, that’d be great. I’d rather be educated than remain ignorant if I’m wrong. Otherwise, why just post a one-off “I doubt” and not explain your thinking?