make myg/f come 7 times but i cant when she wants

yeah im kinda stuck here i had sex with my girl friend and can make her come multiple times but she has a fetish for cum loves it wants it on her face wants to taste it touch it play with it ,but I just cant cum I don't know what it is is it just me this was like the first girl i had sex with and also that happened our second session,so is it maybe that since I'm uncomfortable or something some how i cant cum for her idk please insight pleeeeeease i need her satisfied want her done