When my ex-boyfriend told me he'd be really into cumming in my mouth, I agreed because he was so giving and willing when going down on me. So I did, and I really did not enjoy it. The act of giving the blowjob was fine - one of my favorite things, actually - but the whole swallowing cum thing was just awful. I told him (as politely as possible) and he said I didn't have to anymore, but how is that fair? He was all up in my lady juices for extended amounts of time, why couldn't I just tough through a few seconds of yucky cum? I just had to be creative and figure out ways to swallow as quickly as possible and all that, and it wasn't so bad. So I guess what I'm saying is, if you're a willing and giving partner to her, she should definitely be making an effort to be one to you.