pain while fingering???

ok so this im gonna try to make this as short as possible...
im 17 and ive had sex with 3 guys and each time they fingered me it felt okay at first but after a minute or two it started hurting and feeling uncomfortable and i always end up pulling their hand out but they think it's because i came 😂. how do i reduce pain and make it enjoyable??? sex doesnt hurt at all (it actually feels good) so if i can handle a frickin penis why does a finger or 2 hurt?