Does a Sensual massage always involve a hj? If I saw an ad for a sensual massage will that imply that i can also get a hj?

There is no guarantees that you'll get anything at all whether your going to a sensual massage or FS provider.  You can read the reviews and see what others have gotten and hope your experience is like theirs.  It usually will be.

A provider who advertised with the word "sensual" and didn't deliver a HJ would have a lot of irate customers.  Of course it does not guarantee that she will remove any of her clothing, or allow touching even if she does remove some or all of her clothing.

Come to think of it, I did go to one MP (in Quebec City of all places)that seemed to offer sensual massage but by that all they meant was that you could jerk off yourself while she massaged you.  She did undress fully on  the other hand and she even let me touch her, but she drew the line at her touching my cock.

There's a lot of shades of gray out there.

For gals who do strictly non-sexual massage, the key term to look for is "theraputic" in the description.