First dates are already terrifying enough as it is, so let's not try to make them even more nerve-racking by committing some major faux pas . Going out seems pretty straightforward, but there are some things you just can't do or say — otherwise your first date  may turn into your last. Check out all of the crimes against dating below, and make sure that you aren't guilty of making these mistakes. Crisis averted.
Source: Columbia Pictures 
Talking about politics.
Political discussions usually end in heated debates. Ask your date about presidential candidates some other time.
Checking your phone all the time.
The focus should be on that date, not Facebook.
Source: TLC 
Giving him too much information.
The dinner table is not the time to give your date a preview of what you're like in bed.
Drinking too much.
We know first dates are stressful, but getting plastered is definitely not classy.
Getting overly emotional.
Try not to scare anyone away with incredibly deep topics that will probably get you all choked up. Tears and appetizers don't mix.
Or showing no emotion at all.
At least prove that you are a little bit interested in the conversation.
Discussing serious relationship topics.
Try not to get into marriage until the third date or so — at least get dinner first.
Eating food off of your date's plate.
C'mon, it's just rude.
Dressing in your most scandalous outfit.
OK, you can dress sexy . . . just leave something to the imagination.
Automatically assuming you will be getting some action.
It's the first date! If you don't have sex — or even kiss — that doesn't mean there's no future.
Talking about your ex.
It will just make the person on the other side of the table feel extremely awkward. Nobody wants to date someone that's still stuck on an ex.
Being really negative.
It's kind of a conversation killer.