When the girl said "we always end up in your room"... sounds like she don't wanna have sex then? my present girlfriend is a divorcee and she admitted that she bear 2 children but very seldom she came to her cllmax with her husband and with her 3 other relationship before she got married. So she said that she's having sex with her ex-husband and the others just because of the "obligation".
Anyway, now I have her, she is enjoying my company and she always finishes our lovemaking with a "smile". Here is the trick, she is the type of girl who takes time before she burst, if you don't know it, every time you will reach your cllmax she will just fake you as if she's done too, with all these moaning and squeaking, same time as yours, BUT DARN NOT!!! If you don't want to ask her point blank if she “come” with your style, then try not to use your shaft first and just prolong your foreplay by licking her passionately, if it takes 10-15 minutes and she burst, then she’s normal but if it takes you 30 to 45 minutes with full clit concentration and other stuff (you know what I mean) then she’s one of those “long players” and you need special attention to keep her “libido” high, if she’s “hot” then the rest will follow. I am saying this because my ex-GF is the same and she’s the one who told me how to satisfy her. You need to find the way how to take these girls to cloud 9, sometimes penis alone won’t work with these special doll, you need to know how to make them wild and once they’re hooked on you, then it’s pay back time! They will do the job, for you to do what others CAN’T! It is my personal experience anyway, that maybe applicable to your situation, I hope it helps.