Actually, we aren't together and we never have been

[rashea]

It is also possible that these fellow wine tasters only see you at wine testings, and whenever you are there Carl is there. Carl probably tries to sit near you. So the other tasters begin to associate you two together.  Carl may also talk to you and talk about you.  So alot of this could be because of all that and not necessarily because he is explicitly saying anything.

Again,  it's actually pretty offensive to start assuming people are "together" simply because they are of opposite gender and spend time within a few feet of each other now and then.

But it seems like people are asking, not assuming in this case.

[Danika]

It is also possible that these fellow wine tasters only see you at wine testings, and whenever you are there Carl is there. Carl probably tries to sit near you. So the other tasters begin to associate you two together.  Carl may also talk to you and talk about you.  So alot of this could be because of all that and not necessarily because he is explicitly saying anything.

Again,  it's actually pretty offensive to start assuming people are "together" simply because they are of opposite gender and spend time within a few feet of each other now and then.

But it seems like people are asking, not assuming in this case.

And if Carl has actually indicated that he and OP are dating, it's noteworthy that folks are still asking her to double-check, rather than just believing him. It tells me that they already doubt his story, for some reason.

[MrTango]

If someone asked me if I were dating [person], my response would be "No, why?"

If I got the impression that [person] was claiming to be dating me, my response to that question would be "[person] and I are not, and have never been, dating."

If that makes [person] look bad, then too bad for [person].

[Marguette]

Here’s how it would play with me:

WineTaster: Where’s Carl?
Me: No idea.
WineTaster: [says something that suggests we are boy/girlfriend]
Me: What? Where did you get that idea? No way! I never even see him outside these events.
Winetaster: Well, Carl said…
Me: <snort>