[Beckeh]

My apologies for making an entire thread about this as I'm sure it's been asked in some form, but it was a tricky one to search for.
To summarise, I'm 19, we've been together for 18 months now and have been sexually active for about as long. One thing I can't seem to do anything about is pain in the sort of positions where my legs are both raised and apart. It just feels.. stretched and sore. If I get my hips at the right angle (as in, not such a steep one) all is a-okay, otherwise... no.
My question is quite simple, is this "one of those things" or is there something more I can do? This is experienced even when I'm at the point that I'm aroused enough that nothing else is uncomfortable at all.
Thank you.