
No, a party SUB implies it's a party.
The Big Bang Theory Season 9, Episode 21

It just said "Italian SUB."
The Big Bang Theory Season 9, Episode 21

...with a chicken-carbonara SUB
at Quizno's.
The Big Bang Theory Season 1, Episode 3

No, at the SUB shop,
we were only making out.
The Big Bang Theory Season 1, Episode 17