Honestly, my boyfriend's dick is about 8inches (I measured hehehe) and it hurts at times, there are some positions we can't do because it just goes too deep for me. I've been with guys who have almost HALF the size of that and I couldn't bring myself to fuck them..it'd be a waste of time on my part lol but he was great at oral sex so I still hooked up with him+. I'd say 6-7 inches is the perfect size. I dunno, it really does matter how you use it though, if I wanted a dildo I'd have bought one.