Tabasco flavor without pain?
The heat provided by capsaicin really is a pretty unique one that seems to have a lot to do with how it binds to pain receptors (see Aaronut's answer from a previous thread).  I think this component would be pretty much impossible to replicate with a substitution, unless you want to physically burn yourself on your meal.  You could experiment with alternative sources of strong, pungent flavor like garlic, ginger, black pepper, and horseradish, which are similar but certainly distinct.  Chinese-style tacos, maybe?

That said, Tabasco and other "pepper sauces" like buffalo sauce often feature vinegar as one of their primary ingredients besides chili peppers.  A few dashes cut with a bit of olive oil may help replicate some of that sharpness; think a strong vinaigrette.  It won't be quite the same, but it will help recapture at least one of those elements without causing harm to your unfortunate partner.