Can you still fuck your stepbrother, if mum knew!

What was he thinking? He has a TV in his room, why does he have to watch something on the TV in the living room now that I want to watch a film? Since I didn't want to be driven away, he got a bit angry so he said I could watch if I blowjobed his cock now. Excuse me? I'm supposed to blowjob my stepbrother's cock? How crass is he? I didn't really feel like it but he didn't care, he just pushed my head down. Well then I'll just blow him a little and hopefully he'll come off again, I thought, but no, he wanted more. How cheeky but if I get spoilt too then I think that's great. But oh my God, I really let my stepbrother fuck me, is that borderline????