Can I have your digits?

Yesterday evening I was at the pub after church; and as usual, we were engaged in a random assortment of conversation. Our table was joined by one more member of the community who quietly took a seat on my right.

In the middle of some discussion about music (or something), W abruptly picked up his mobile, looked me in the eyes and asked, "Can I have your number?"

I was taken quite aback for a couple seconds. I'm not accustomed to gentlemen asking me for my number, in fact, I've never been in such a situation before.

"What are you going to do with my number?" I asked. (Some of the smartest and best people answer questions with questions - and so when in doubt, I emulate.)

"I'm going to send you a text." the unfazed W replied.

"What will you text me?" I continued to buy some time to think about this.

"You'll see." said W confidently as he readied his phone.

I looked helplessly at C. "Should I give it to him? Is he an okay person?"

C, a very laid back, older gentleman (who, incidentally, works at the Houses of Parliament), slightly shrugged / grinned and said "I think it'll be all right."

I said out the numbers and the conversation resumed. In a few seconds, my mobile beeped its receipt of a new message: [Name of man sitting on my right] periodically falls for a girl at church. Just a heads-up. He is very harmless, but information is useful. x

As W finished his last, rambling thought about thresholds, I said "Thank you for letting me know."

"No problem." he said.