Ask Dan & Jennifer

Kristina, that is a good question. I understand where you're coming from. But I also like to play devil's advocate. I don't know what your sex life is like, so this is all hypothetical. If you are having sex in the same way all the time it will get boring. Also, different positions have different stimulation on different areas. You have to know your own body for one, to know how you get pleasure, and you need to know his body to know how he can get pleasure. Perhaps it's a matter of nerve endings in his penis, they're just not getting stimulated in having sex however you're doing it, but when he masturbates it may be getting the right stimulation where he wants it. Also, foreplay is very important for sex, usually noted for women, but some men need it to orgasm during sex as well.
Now, on the other hand, if you are trying out the whole kama sutra and then some and giving plenty of foreplay time then we'd have to look elsewhere. As for hisporn watching, this may help.

Or if it's more of a concern of over use of porn this one may be interesting to you.

Now, I have a question for you, you say he wants to ejaculate inside of you. Are you on birth control, or are you looking to get pregnant? This is a biggie, if you are on birth control, good, make sure you use it properly and follow all guidelines etc, etc. Then if you aren't, think about getting pregnant, is that something you want to do right now?
Also, I noticed you called him your partner, is he a boyfriend, fiancee, or a friend with whom you have sex? I see you say you love him, but love can be friends or more...This can greatly vary what you need to do. If he's a friend with benefits, then I'd say maybe it's time to move on. If it's a more serious relationship, then I believe everything comes down to communication. Have you told him this bothers you? Perhaps counseling may not be a bad idea, as a neutral third party can be helpful in mediating difficulties.
Now, finally, I want to pose the possibility to you of you getting him off, rather than him having to masturbate. Again, this is all hypothetical since I do not know what you have tried. Perhaps giving a hand or blow job would get him off, and you can control what to do with his ejaculate rather than him deciding on where to put it. I can say in my experience, beforehand a guy might have an opinion on where he wants it to go, but when it's happening it's not such a big deal. This may help too. Dan and Jennifer have a lot of other great vids and articles out there too. I hope they don't feel I'm plagiarizing them by just posting links to their stuff.

I hope this helps, if not, I'm sorry, someone else may have a better answer.

K, these are some really great points.

Dan and Jennifer have a lot of other great vids and articles out there too. I hope they don't feel I'm plagiarizing them by just posting links to their stuff.

Just wanted to address this - nothing makes us happier than to see someone find our articles, videos, whatever useful and share them with someone else. That is very, very cool, and largely it's why we do why we do.

Please, quote and link all you like, the more the merrier. That's what it's there for. :)

Dan