Your sense is not a stretch, although a bit too precise in the "simultaneously on both sides (above the hips, below the rib cage)" element.
- slang. To poke, tickle, etc., (a person) in a sensitive part, esp. the genital or anal regions; sometimes, more specifically, = fuck v. 1.
....
1906 Dial. Notes 3 138 Goose, to create nervous excitement in a person by pointing a finger at him or by touching or tickling him and making a peculiar whistle.
1932 J. T. Farrell Young Lonigan v. 205 Paulie slapped Denny's face. Denny bawled... Paulie goosed him. Denny squirmed.
...
1967 E. Partridge Dict. Slang Suppl. 1152/2 Goose, the predominant post-World War II meaning is ‘to jab a finger in ano, in order to surprise or annoy’.
["goose, v.". OED Online. September 2015. Oxford University Press. http://www.oed.com/view/Entry/80030 (accessed September 18, 2015).]
As you can see from the sequence of quotes and the meaning of the final one, if your sense was transmitted to you by someone, a grandparent for example, who learned the term before the end of WWII (during which the sense of 'to goose' was considerably vulgarized by soldiers), the sense you learned would correspond with what that person was likely to have encountered--aside from the precision I already pointed out.
Nonetheless, your use of the term with the sense you learned is now much more likely to evoke the more vulgar sense than what you intend, even imprecisely (a simple poke to startle)...although I, for one, depending on the context (and particularly the speaker or writer) understand it in the general sense "to poke, tickle, etc., in a sensitive part", rather than the more specific, vulgar sense commonly used.
If you're looking for a replacement phrase or term, what I've heard used is "a poke in the ribs", as in
1949 Lockhart (Texas) Post-Reg. 3 Mar. She laughed and gave him a discomposing poke in the ribs.
This is the common contemporary phrase closest in meaning to your sense of 'a goose'. Obviously it moves the location you specified upward on the torso, omits the simultaneous duality of your poke, and doesn't accommodate concise verbal use.
Best Answer
The person ...
tends to get the wrong idea.
is tone-deaf in relationships.
is not good at picking up social cues.
confuses friendship with romantic intentions.
always assumes you want more.
turns everything into a date (works best if the person is female).
is a little creepy (works best if the person is male).
is too touchy feely (works best if the person is a male).
is over-familiar.