Don't be Rude when you Tell People when to Meet you

Here is a quick English quiz - can you see the problem in the following conversation?

     - Do you want to have dinner with me tomorrow?

     - OK, that sounds good.  When do you want to meet?

     - We will meet at 7 o'clock.

Did that seem strange at all?  The grammar is perfectly fine, there are no mistakes here.  But it's not natural and it would confuse me if I heard it.  Here is a more natural version of the exchange:

     - Do you want to have dinner with me tomorrow?

     - OK, that sounds good.  When do you want to meet?

     - Let's meet at 7 o'clock.

The problem with the first version is that by saying "We will meet at 7 o'clock." you are taking away all the choice from the other person.  This is an unplanned invitation, so you need to get confirmation by saying "how about 7?" or "let's meet at 7." or something like that.  

It's OK to say "We will meet at 7 o'clock." if it is a pre-planned event, like a party or something.  This one is correct:

     - Do you want to come with us to the party tomorrow?

     - OK, that sounds good.  When do you want to meet?

     - We will meet at 7 o'clock.

In this case it's fine because the party is scheduled for 7, there's no need to get confirmation from the other person.  So good luck and be nice enough to give people a chance to say yes or no when you ask them out!