[PietJan]

Not abnormal, I lose my erection during a blowjob for unknown reasons. I can face fuck her but as soon as she starts giving me head my penis loses its erection. I probably just get overexcited and the adrenaline gets to me since I haven't really had blowjobs before and I need to get used to the extremely horny stuff. (once again; adrenaline is a killer)

You can work on the orgasm timing by "teasing" yourself (by playing with her or letting her tease you) and making yourself really horny before letting her do the real work. Don't wait too long if you get really horny, the moment you're having a real problem controling yourself is when she should start. After that you might run in the not-horny part after being horny which stays for a couple of minutes.

What works for me is seeing her pleasure herself/me pleasuring her or just looking at her ass for a while.. After that I can come within 20 seconds. And don't get me wrong, I'm not a fast comer. I can just control it by switching certain knobs on and off in my head.