Need sexual advice from the ladies.

how do i go about asking my significan’t other that I like fellatio down there? I don’t want to be insensitive cause I think she’s has some bad experiences relating to that. But i love “receiving.” I love “giving” to her. I could do that all night and not have intercourse. But recieving is a real turn on for me. But because I love her, and want her to feel safe with me, I don’t ask. Please help.