MY JERK BUDDY

As the title implies, I have a jerk buddy. I am 42 years old and we've been at it for a couple of months now watching porn jerking away discussing the films, you know the usual. Well not totally normal he once played with me. Anyway, the other night whilst we were masturbating, he asked if I had ever wanked to gay porn which I have and so said, 'yes'. He removed my hand, lowered his head and started sucking my cock that I'd unknowingly made erect for him. I didn't object in fact I encouraged him, breathing heavily and gasping, boy that feels good, don't stop and the like. As he brought me to climax, I begged him to swallow. 'Please swallow, don't stop, pleeease'. It was over. Well, it was a bit awkward after that but before I left he made it clear he expected me to reciprocate next time. I nodded and left. Back there thursday but I don't think I can unless he makes me. What do you think, any tips, I've never even held another cock, I might chicken out.