No, a lawyer will not necessarily tell you to get a prenup. Most of the attorneys I know think they are a waste of time and/or a bad idea for most situations. Specific situations might warrant them, but there is a whole system of property division laws in place, and mostly they have been hammered out to be as fair and predictable as possible in most situations. None of the lawyers I know have prenups, including me -- if I'd felt the need to do something different with my assets than what the marital property laws provide for, I would not have gotten married in the first place.

Your situation does sound like one where you should talk to a lawyer, though.