[nautical]

SMS number on Twilio => Your webhook => Telegram API to forward message to you and you can reply via same (he receives SMS)

Another person can simply install Telegram

This way you can communicate to both using Telegram, one can talk to you via SMS and another via Telegram.

(Telegram or any other IM supporting API access)

[esac]

Thanks for the suggestion, I didn't think of Twilio=>webook. Telegram is one of the platforms I use daily and something that would distract me but i guess you can replace it with anything else like an IRC client.