I would like to know some more information for my diagnosis.
Are you wearing a condom?
Using lube? (if needed)
What is the atmosphere you all are trying in? (bedroom, kitchen, parkinglot)
Have you all tried dirty talking to each other?
Im only asking so I can get a better sense of wtf your doing. I personally think atmosphere can have a big effect on cumming. Obviously a condom has some restrictions on thats too as does the dry vagina. Also I have certain times when I have recently had a lot of sex or I have used COMPLETELY LEGAL DRUGS
it will take me a little longer to orgasm. My gf usually can notice that it is taking me a little longer and she starts dirty talking to me, telling me how bad she wants me to cum and that alone can take me from feeling like "I will be at this for hours" too "OH MY ****** GOD....."
So maybe its just you needing a push to get there. See if she could give you that push and then blow your load already.