Someone could tell me who is Martin?
In the Carlos dream at the end of the last update.
That is the first time he is mentioned?
*Spoilers*
It was covered as a hint a couple times, moreso in the latest update, but Martin was a 23 year old guy who introduced Carlos to the concept of homosexuality when he was younger. (The implication behind this is that Carlos was underage at the time, and some phrasing suggests Martin kind of forced Carlos into it--Not SA, but not all that far off either. This is why Ben never brings it up: that's a very awkward conversation to have.)