Echoes, I think it's worth talking it through with him to see how you both feel about it. He's a pretty solid guy, so I don't see red flags either way. My T doesn't charge me for outside contact, and occasionally our calls have been lengthy (like half-session length or more). Over the weekend she realized she had completely misinterpreted something that happened between us, and she called me to make it right before our session the next day. (I think it was a totally forehead-slapping moment for her.) So it doesn't seem weird or odd to me if he is okay with not asking for or accepting payment for the Skype call, but it kind of depends on what feels right to you.