I can appreciate how truly foreign something like tango is to a non-dancer. As tempting as it is for me to say, "You guys must have other issues if the dancing bothers you," I have to instead say, tango can be a big pill to swallow. Bodies can be very close, depending on the style, and there is also a spiritual feeling or connection that you often hear people talking about. It is intimate. But, is it sexual? I would like to say, no.
Not everybody, even the dancers, are as mature about dancing as we all like to say we are. Yes, probably, some of the women enjoy hanging on your man out there. If you were to learn tango then yes, probably some of the men would enjoy having a chance to hold you in their arms for a few minutes. But, for those of us who truly love the dance, we are only interested in the dance and how the dance makes us feel. When I sense this sort of "hey, baby" vibe coming from my partner, I completely ignore it and instead enjoy other things about what he is giving me. It has never been a problem for myself, the men I dance with, or my boyfriend.
I am very, very fortunate to have a boyfriend who dances as well. Tango is something he loves very, very much. I think the only time jealousy has become an issue for me was as a beginner, it would irritate me to watch the actions of the women after the dance. They'd gaze into his eyes, hold onto his arm just a little longer than I would like... but we talked about it. He knew it bothered me. It was just something I had to get past as a new dancer. It was just part of the growing process.
Maybe you should give tango a try. Just to see. I do know that social dance is not the best hobby for all. Some people just can't get past the touching. And, that is okay. It just means there are other things in the world that are better for you than dancing.