why cant i finish /u/EmotionalAmphibian12 Sex

so i (female 18) have had plenty of sexual experiences but for some reason i cant cum from anything. Like at all. Ive had really good guys who actually know what they are doing but for some reason i just cant seem to actually finish. I always have to fake it lol. I dont know if this is normal or not but even with my ex girlfriend she could never make me cum i had to fake it. I can sorta cum with myself but i dont actually masturbate i cross my legs and rub my thighs together and it feels good. I feel bad sometimes cause i dont want it to seem like i dont actually enjoy it but i do think it would take hours to actually make me finish but guys cant go that long lol. How do i fix this :/

so i (female 18) have had plenty of sexual experiences but for some reason i cant cum from anything. Like at all. Ive had really good guys who actually know what they are doing but for some reason i just cant seem to actually finish. I always have to fake it lol. I dont know if this is normal or not but even with my ex girlfriend she could never make me cum i had to fake it. I can sorta cum with myself but i dont actually masturbate i cross my legs and rub my thighs together and it feels good. I feel bad sometimes cause i dont want it to seem like i dont actually enjoy it but i do think it would take hours to actually make me finish but guys cant go that long lol. How do i fix this :/