It's fair enough to realize your vote doesn't matter. Depending on your state, it does nothing and even in a swing state it basically doesn't matter at all.

I am dubious about them finding out you are lying about it though. I mean, how often do you think this will come up after the vote is done? I really doubt your friends will keep asking you if you really voted for Joe after the vote is concluded. And I disagree that there is no point in being principled. I know being principled also does nothing for the outcome of this vote, but sticking to your convictions is good for your own head, while being browbeat into voting like your friends so they still like you isn't.