Making love is a partnership. For the partnership to work well, we need to teach each other how we masturbate so that we can learn to mimic the unique and specific movements, motions, and pressures that each of us has come to rely upon. If we're off the mark a bit, either the resulting orgasm will not be what we expected, or, it won't happen at all.

We do not give orgasms away. All any of us can do is help our partner achieve his/her own. To do this we must learn what works for them and this takes communication and some practice. Without communication and feedback, all any of us can hope for is a 50/50 chance of being right. With something so important, who wants this as a batting average.

My recommendation is for the two of you to demonstrate for your partner how each of you masturbates and then to take each other's hand in yours and guide your partner until they learn to mimic your unique and specific movements. When we can do this we can help our partner attain their orgasm reliably and regularly.

As noted elsewhere, the reason dry humping may be working so well is that the two of you are applying the friction where it will do the most good, rather than by possibly meandering around hit and miss with your finger or tongue. Just guessing. For fingering to work and for oral stimulation to work, you have to know where to do the stimulation and this often changes as her level of arousal changes.

i would think it is because she wants it to last longer with you. Maybe when she dry humps she is just having small ones. Just try to find her special spot that the dry humping hits and your finger or toungue does not. Just my sugestion.