[Age of Ignorance]

I don't know if the Magnum that comes to my mind is the same as the one you mentioned in your post. Here in Australia, a magnum is an ice cream - not sure if that is something he would want to put on his penis.

Humour aside, a sexual relationship is one of mutual respect for boundaries. A penetrative experience is just plainly not enjoyable if the boundaries are stretched to their max or breached in any way (I'm oddly reminded of the time my ex-girlfriend attempted to jam her finger in my anus, on multiple occasions, despite my protest). Neither is having someone around that is consistently looking to cross the line. Yet, my advice isn't to end the sexual relationship all together, if you enjoy it in principle, but ensure that he maintains a realistic approach to these things. He needs to take a look, long and hard, at himself and his actions. One way to do this is to cut him down off his high horse - he might think he can fit into a "magnum", but have you told him that he is just not big enough for it?

The pregnancy issue is a little more difficult. The point where I started to think about safe sex (because I was impervious as a kid, though I still used condoms and ensured safe sex was practiced) was when my sister, two years my junior, fell pregnant at 15 - a product of no contraception and a lack of experience. It's experiences like those that make you think about the possibility that it could happen to you. You've obviously had a similar experience, but he doesn't seem to have caught onto that. I would advise you to sit him down, talk to him about that, and re-evaluate where you stand after that. Perhaps he'll understand if he hears the scare you had at 15 and how you don't want to go through that again.

If not, dump his ass.