Because there are less things getting in the way of communication. Preconceptions about looks, the way you dress, your voice. If you're shy.

It's a communication between minds, which is generally much more truthful. As far as lying goes, it happens the same face to face or on the internet.

It doesn't mean anything.
You need to have a talk to discuss what it does mean.
If he can;t be direct and honest about what that means, then he;s not ready for a relationship at all, and if you can;t ask, then neither are you.

In my long (40 years of adulthood) experience, I've never had anyone ASK to be my boyfriend. It just evolved from seeing each other and getting to know each other, until one or the other of us brought up the question of being exclusive.

ASK the question of him–not us!
How would we know?

When a guy if fully erect from sexual stimulation, the muscle that controls urine from the bladder to pass through the the urethra is supposed to be sealed so that seminal fluid can pass through during climax.

If he is able to urinate while fully erect and engaged is sexual acts then that muscle is not closed.

Go see the Doc.